Deteriorating CL tune

[joe_lyons]

With all of this talk about tunes going to crap after they leave and run on the road for a while i have a couple of questions for those people.   If you did vtune, PV bt, or sepst ST and had this happen did you monitor the a/f while recording and see if the dyno/controler matched the a/f value that the ecm was trying to achieve?  I ask because i have done quite a few vtune, PV bt and sepst ST and havent had any issues.  I have had quite a few bikes that if there was a difference between the two readings then in those areas (usually 20- 35 kpa) then i would just do that area in open loop and leave the rest cl that matched up and read well and ship it.  But i always use the dyno sensor to double check what the stock sensors are reading.

[mayor]

great thread Joe.     this is a topic I'm interested in hearing more about as well. 

[FLTRI]

Joe,
Thanks for the post.

This has been my experience as well. If the o2 readings are good enough for v-tune, etc they will be good on the street.

All this bad crap we hear about started before v-tune and some tuners liked to tune rich...to the point the o2 sensors would drop out.

Or the tune was inadvertently left with a big super lean area(s) where the o2 sensors also dropped out.

So those who took the time figure the actual reasons for closed loop failures soon realized the exhaust mfgs were not doing anyone favors with their first go around with sensor placement which also added to the unreliability of the sampling.

Now we are some 3-4 years later and most all the sensor placement issues have been addressed...some more effectively than others.

Those pipes with issues need to be compensated for by leaving crappy reading in open loop...or fix the problem which can be expensive for the customer. I'm not convinced the $$ is worth the improvement.

If the sample is reliable use closed loop, if not open.

I find exhaust mfgs who actually test for proper o2 signaling also make the best power
D&D - Thunderheader - Bassani - Drago - Cycle Shack
Each one of those mfgs, once they realized the sensor needs to be in the exhaust stream,  immediately took steps to correct the placement.

Bob

[wurk_truk]

I agree it's the pipes.  Especially the 18mm bikes.  The stock location was not that great once free flow cans were installed.  All the mfgs copied that location.  With restrictive cans, things worked.  Changing locations and depth worked wonders.

Once the 12mm pipes came along, those sensor positions were way less critical. AND, those that made dual bung pipes had better placement.

Even the 09 pipes sucked.  AFVs would screw up the tune.  Sepst and tts, both came out in those 18mm days, and we had to learn what was happening before it could be addressed.back when 205 cals were it.

Some gave up.  Others figured it out.  Using the ecm along with the provided software to plot VEs works well, v tune and pv tune schemes.  Like Bob says, open up trouble areas and leave decent areas CL.  Some pipes simply suck.  Leave then open loop and move on.

I see it as a non issue anymore.....  but it took a few years......

Sent from my SCH-I535 using Tapatalk 2

[laserp]

I have 2010 Limited, with the jackpot 2-1-2, dyno tuned muffs on a 103 @10.2 andrews54, TTS. The pipe has the stock located narrow band sensors. Are they located in the right spot and the right depth?

I used both the vtune and the twin scan 2+. Struggled a little with the TS.. bungs up at the exhaust ports... chased my tail in the light load areas. Seemed like the vtuned did a better job.

Laser

[Jeffd]

I have 2010 Limited, with the jackpot 2-1-2, dyno tuned muffs on a 103 @10.5 andrews54, TTS. The pipe has the stock located narrow band sensors. Are they located in the right spot and the right depth?

I used both the vtune and the twin scan 2+. Struggled a little with the TS.. bungs up at the exhaust ports... chased my tail in the light load areas. Seemed like the vtuned did a better job.

Laser

by all accounts the jackpot headers have the correct 02 sensor placements.

[Jamie Long]

I have 2010 Limited, with the jackpot 2-1-2, dyno tuned muffs on a 103 @10.5 andrews54, TTS. The pipe has the stock located narrow band sensors. Are they located in the right spot and the right depth?

I used both the vtune and the twin scan 2+. Struggled a little with the TS.. bungs up at the exhaust ports... chased my tail in the light load areas. Seemed like the vtuned did a better job.

Laser

The Jackpot 2/1/2 has the 18mm/12mm O2 bungs located in optimal locations at the correct depth. This is something we not only tested thoroughly when we developed this pipe back in 2009, however we work with this pipe extensively in and out every day in a wide range of applications using nearly every tuning product on the market.

[Jamie Long]

Sometimes it seems to be more than location of the bung.  Take the Jackpot header. Bungs do look good. Sampling is great with decent slip-ons at 30-40kpa. Take slip-on and run them as open headers. You will never get a good sample. Pressure in the pipe is the problem, or lack of.  Not location.  This is the extreme example, but plays into some slip-ons will not help you collect data at lower kpa. Tab comes to mind.

You are absolutely correct. Looking at the big picture O2 sampling is only as good as the rest of the combination and the tuning strategy itself. Components such as mufflers, cam design, how the engine is setup, and a wide range of other variables will affect the tuning characteristics of an exhaust system on several levels. Many times what is blamed on improper O2 signaling or an issue with a tuning product is actually a sign of an underlying issue with the specific combination being tuned, the base calibration itself, or ones completely relying on O2 sensors to develop the tune.

[joe_lyons]

Has anyone had any issues with the bung style/location that harley and V&H use for the 12mm on dyna, ST and some VH touring?  I dont know if it is just a cosmetic/easy angle thing or that the radius of the bung helps with the proper signal.

[laserp]

Thanks for the feedback on my question guys. Good news!
Laser

[joe_lyons]

So I'm guessing that no one has had any issues with stamped bungs?  Must be a radius thing with the bung to help get good signal kinda like a plane wing?

[hrdtail78]

I didn't have a problem with the new style. Got another one tomorrow. Same new style.  Different builds with different slip ons.  If I had to guess why? I'd say looks and the stamped are cheaper to make and gotta be easier to weld in.  Be a great piece to sell separately. 

Just when I was building good confidence in a popular 2-1-2.

[joe_lyons]

For sure on the fact that its cheaper.  That's the force that drives many decisions.  Guess you could cut a ton of of then out of stock dyna and ST  exhausts and sell them.  But sometimes a cheaper choice can work well too, but not very often it seems.

[hrdtail78]

Got a potential customer that has a 2013 softail and RH 2-2 new in box from eBay.  I looked them up and have talked to RH.  RH stated the adapters I needed would be great. Never seen a problem.  So.... I can either weld in bungs or use a modified adapter I'm thinking about. 

[Hilly13]

CL tune will only change if something ain't right, I ride my bike at least 5 days a week to and from work most weeks of the year which is lots of oppertunity for the tune to go south, but in truth it is the opposite, now the sensors are in the stream as they should be the tune don't change, before the 02's were right it did drift, now it dont, so much hot air about this, gotta wonder what the motivation is, my closed loop area is small but the bike does run there a lot, maybe I'm missing something, might have been that frontal lobotomy 

[joe_lyons]

Got a potential customer that has a 2013 softail and RH 2-2 new in box from eBay.  I looked them up and have talked to RH.  RH stated the adapters I needed would be great. Never seen a problem.  So.... I can either weld in bungs or use a modified adapter I'm thinking about.

I would be weary of adapters for the sensors for sure.  I've even seen 18mm to 12mm adapters they must work great lol.

[FLTRI]

I would be weary of adapters for the sensors for sure.  I've even seen 18mm to 12mm adapters they must work great lol.

Yep, I've seen those jewels! Unbelievable what crops up in the aftermarket!
Take a questionable length bung and add an adapter which, for sure, gets the sensor out of the exhaust flow.
Bob

[hrdtail78]

The ones I'm looking at are basically bung plugs with 12 mm threaded hole in the middle instead of the Allen port.  I was looking at turning down the hat portion and threading it onto the sensors. Then threading the sensor into the 18 mm bung. I can get a better plan of attack when I actually get the pipes to my shop.

[FLTRI]

Jason,
If the 12mm sensors are placed downstream as with stock locations and into the stream will produce reliable results.
If the sensors are right outside the exhaust port and/or not into the stream it's just a guess as to results.
Just my experiences,
Bob

[rbabos]

The ones I'm looking at are basically bung plugs with 12 mm threaded hole in the middle instead of the Allen port.  I was looking at turning down the hat portion and threading it onto the sensors. Then threading the sensor into the 18 mm bung. I can get a better plan of attack when I actually get the pipes to my shop.

That should do the trick. Depth will pretty much match up for what you need then.
Ron

[wurk_truk]

putting the 12mm ones near the ports will smoke em up.  I don't think the heater circuit will take that amount of temp.

Looks like you get a chance to weld better than I do... again.

Azzhats and cheap pipes STILL make life miserable for us, and I just had told Ron this crap was on the wane, too.

I THINK, don't know for sure, that I MIGHT be a dick about pipe buys like this.

I will be VERY interested in what bungs to use for the 12mm pipes, if they DO need welded.

[rbabos]

putting the 12mm ones near the ports will smoke em up.  I don't think the heater circuit will take that amount of temp.

Looks like you get a chance to weld better than I do... again.

Azzhats and cheap pipes STILL make life miserable for us, and I just had told Ron this crap was on the wane, too.

I THINK, don't know for sure, that I MIGHT be a dick about pipe buys like this.

I will be VERY interested in what bungs to use for the 12mm pipes, if they DO need welded.

Too close, you are probably right. Vrod runs them around 10" from the port without any ill effects Ive heard about.
Ron

[joe_lyons]

putting the 12mm ones near the ports will smoke em up.  I don't think the heater circuit will take that amount of temp.

The mini sensors and the large sensors have the same heat range so I don't think that it would "smoke them". But I thought it was about the sample timing.  I think from the factory the location is a lot about ease of access and some proper location.

[wurk_truk]

I'm not buying that, Joe.  The heater circuits can't take that much temp.  Or it can't take it for long.

There is a reason, after all, MOCOC decided to use heated O2s... that being EPA...  and after THAT decision... they moved them downstream.

[FLTRI]

I agree with Joe. It's more about polling time differences between calibrations.
By moving the 12mm sensors right outside the port the heater circuit could be eliminated because they would get heated by exhaust.

The MOCO had to do something as the 100,000 mi sensors die much earlier (~10,000-~25,000) due partly to excessive vibration and possible, external heat soaking, even sooner if AFR is too rich.

Moving the sensors down stream hopefully helps to keep them alive longer but they have to heat them to get them on line earlier...yes EPA but not a bad thing.

Bob

[joe_lyons]

Delphi literature shows 450°C for both.  The ST & dynas have the mini sensors much closer to the port than the touring but mabie that's what the stamped bungs do is to shield the heat?

[FLTRI]

Delphi literature shows 450°C for both.  The ST & dynas have the mini sensors much closer to the port than the touring but mabie that's what the stamped bungs do is to shield the heat?

No problem with placement differences as long as polling times are commensurate with placement.
Arbitrarily changing O2 placement 18mm or 12mm assuming CL system operation will be correct is IMO not good.
Bob

[wurk_truk]

Yup,  but even the dynas are still a foot from the port.  If using adaptors, they will be IN the port, this is what I am thinking.

Sent from Buckeye Tuning

[Tsani]

Well this is a issue I am working on now. O2 placement. I have a set of stock 07 softail (FLSTNI) header pipes. The original placement stinks in my opinion. May work ok with stock mufflers but not with my Cycleshacks. Was looking at the setup in a 2013 FLSTNI and they are now putting the bungs pretty far away from the exhaust ports. Now I know the two wire O2s I am using are different from the new ones, the bung location in the stock 07 setup has to put them pretty much out of the flow especially the front one which is right after the inside radius of the first bend. I can imagine that the exhaust flow almost creates a dead spot there with a more open exhaust. The rear is probably ok, just need to correct the fact that the stock bungs do not allow the tip of the sensor to be in the flow adequately. I just got some low, fully threaded bungs and am going to place the into a stock head pipe. The front location is the one I am having a hard time deciding on as it will have to go on the inside area of the pipe (frame side). Yeah I know, the outside of the ppe would be better but I do need to consider looks as well.

[FLTRI]

Well this is a issue I am working on now. O2 placement. I have a set of stock 07 softail (FLSTNI) header pipes. The original placement stinks in my opinion. May work ok with stock mufflers but not with my Cycleshacks. I just got some low, fully threaded bungs and am going to place the into a stock head pipe. The front location is the one I am having a hard time deciding on as it will have to go on the inside area of the pipe (frame side).

Is there some of the bung you can take off? Just getting the sensor deeper into the pipe at its present location may be enough to get good readings.

That said, if you intend to relocate remember to make sure the sensor nose is pointed downhill not uphill as you don't want condensation to gather. Water can kill an O2 sensor.

It would not be the end of the world if you identify the closed loop problem areas and tune them from where you are now. Usually the problem areas are found below 40 kpa. Above that exhaust pressure should be enough, even with cycle shacks unless you have bent the tab inside. There should be about 1/4" at the widest part of the opening.
Bob

[joe_lyons]

Yup,  but even the dynas are still a foot from the port.  If using adaptors, they will be IN the port, this is what I am thinking.

.
I think this is closer than a foot

[rbabos]

Yup,  but even the dynas are still a foot from the port.  If using adaptors, they will be IN the port, this is what I am thinking.

.
I think this is closer than a foot

Interesting. I notice my v rod has a similar fabbed pocket in the pipe. Shooting for the same goal likely.
Ron

[joe_lyons]

All of the softails, dynas and vrods have these o2 bung setups stock and Vance and Hines is using them also

[wurk_truk]

In answering Hrdtail78s question, in is NOT good practice to use an adapter and place a 12mm sensor into a bung made for a NON heated sensor.  The heater elements WILL burn up if too much heat is applied.  C'mon dude, just think logically for a moment.  A heated sensor exists why?  Our 18mm sensors are from 1976.  They were designed to get as hot as possible as fast as possible... from the HEAT generated by the exhaust ports...  and the auto companies got tired of having to replace these because of thermal shock and all of that.   Heater circuits allowed the O2s to come online way faster to control things faster (less emissions).  The heaters HAVE to toggle the heat on and off.  CAN"T run a heated sensor at a higher temp than the heater circuit.

[rbabos]

In answering Hrdtail78s question, in is NOT good practice to use an adapter and place a 12mm sensor into a bung made for a NON heated sensor.  The heater elements WILL burn up if too much heat is applied.  C'mon dude, just think logically for a moment.  A heated sensor exists why?  Our 18mm sensors are from 1976.  They were designed to get as hot as possible as fast as possible... from the HEAT generated by the exhaust ports...  and the auto companies got tired of having to replace these because of thermal shock and all of that.   Heater circuits allowed the O2s to come online way faster to control things faster (less emissions).  The heaters HAVE to toggle the heat on and off.  CAN"T run a heated sensor at a higher temp than the heater circuit.

Intersting. I always thought the heated sensor was more of a preheat device to speed up the time it takes for the exhaust to bring it up to operating temp. After calibrating the wide bands that I've used with heaters I can still put my hand on them after. As you pointed out, I'm a crowbar mechanic when it comes to electrical crap but this observation has me leading to O2 heaters as more of a preheat device to speed up control on a started engine. School me.
Ron

[redmtrckl]

It's discussions like this that I sure miss Steve Cole's input.

[rbabos]

A little more than a preheat device.  There are times when you can cool the 18's enough to send them off line.  Long decel for example.  In this case the 12's heater will kick on and heat them.  I am sure this would be seen more with the 12's down by the trans case if they were not heated.  I had to chase a bad sensor.  Keep the kpa up and the sensor worked fine.  Lower kpa the sensor kept going off line.  New sensor fixed the problem.  I understand this doesn't prove anything about the heater being bad, but... that what it points to for me.

Steve would be some help with this.  But... He also might state some facts and confuse some guys. 

Truk,
You have the best chance living through an ambush if you charge it.

I'll buy that. Sounds like the heated might be better overall then for vtuning or autotuning depending on your Tuner fetish.
Ron

[wurk_truk]

Ron... you are EXACTLY correct.  They ARE a pre heat device to get the engine under control as fast as possible.  This IS for emissions testing purposes, etc.  But, in older crap, the O2s depended upon the engine heat, they placed them as close as possible to the source of the heat as they could... faster operation meant the engine is 'under control' sooner.

No biggie.

Now, though, the newer 12mm O2s DO have the heaters circuits.  They WILL heat an O2 to 1350F from what I have recently read on the Bosch DE site.  (Bosch.USA site sucks).  The 'heater' is regulated by the ECM, eventually.  These heaters are NOT self controlled.  I AM saying that the heater circuit needs to have enough control to regulate that heat.  Too close to the head, and the heater circuit COULD lose control, and burn up the heater circuit.  This IS the why they are moved a bit from the port, so they the heater circuit can see both the low temp AND the high temp and regulate.  AND... what it DOES heat is the Nernst cell inside, not the whole O2 sensor, or that is what a cutaway looks like to me.

ANd, Joe, you are also correct in it is when the sensor is POLLED by the ECM.  Nothing is read 100% of the time.  AN ECM is constructed similar to a PLC and it involves scans and scan rates.  The ECM has an instruction inside to 'look' at the O2 at a certain time after the combustion event.

I called SC  last year to ask about this vis-a-vis a touring bike.  He said the 'polling' takes place in a wider area than exactly where the stock O2s are located.  I would be OK as long as my front pipe was about to the brake pedal and the rear pipe was at the front of the clutch cover.  Also, never have an O2 closer to the 'exit' of the PIPE (BEFORE collector) less than 5 diameters of the pipe in question.

On a Dyna?  I think anywhere up there would be good, but my OPINION is there will be too much heat right next to the valve.

[joe_lyons]

Here is a small amount of info on the mini sensors.

[attachment removed after 60 days by system]

[ultraswede]

Its a shame that Delphi use the term "switching" sensors, since the sensors themselvs do no switching!

The ECU does the switching.

[Hilly13]

Its a shame that Delphi use the term "switching" sensors, since the sensors themselvs do no switching!

The ECU does the switching.

I agree, I think it causes a lot of confusion for some people, the sensor reports a voltage, what is important is when that voltage is checked.

[Scotty]

Its a shame that Delphi use the term "switching" sensors, since the sensors themselvs do no switching!

The ECU does the switching.

The sensor's voltage switches from high to low depending on what it reads in the pipe.

Maybe that is why they call it a switching sensor.

[FLTRI]

Its a shame that Delphi use the term "switching" sensors, since the sensors themselvs do no switching!

The ECU does the switching.

The sensor's voltage switches from high to low depending on what it reads in the pipe.

Maybe that is why they call it a switching sensor.

I believe ultraswede is 100% correct.
The O2 sensor can only read O2 content and send a voltage to the ECM. The ECM decides if the system is rich or lean then adjusts the fueling to drive the system to the opposite.
Ie: If lean voltage output (typically <450mv) the system drives richer fueling. When the sensor reports rich O2 content (typically >450mv) the system drive fueling lean...and the process repeats.
This is why they are called switching sensors but they do no switching...all switching occurs in the ECM.
Bob

[ultraswede]

I used to tune my 5.3 Tahoe with Hptuners.

Since there was one o2 sensor for 4 cylinders and stock cam, it run extremely stable.

If I set the AFR to 14,7-1 open loop (possible on that combo) the 02s would read a steady 0.45v, the graph was straight line.
i.e. the sensors only report a voltage, if the AFR is constant, so is the o2 voltage.

[Scotty]

Its a shame that Delphi use the term "switching" sensors, since the sensors themselvs do no switching!

The ECU does the switching.

The sensor's voltage switches from high to low depending on what it reads in the pipe.

Maybe that is why they call it a switching sensor.

I believe ultraswede is 100% correct.
The O2 sensor can only read O2 content and send a voltage to the ECM. The ECM decides if the system is rich or lean then adjusts the fueling to drive the system to the opposite.
Ie: If lean voltage output (typically <450mv) the system drives richer fueling. When the sensor reports rich O2 content (typically >450mv) the system drive fueling lean...and the process repeats.
This is why they are called switching sensors but they do no switching...all switching occurs in the ECM.
Bob

Hmm your explanation is exactly what I said but you said Ultraswede is 100% correct?!?

The sensors voltage is either above 450mv (rich) or below 450mv (lean) so it reports voltage OR you could describe that as the voltage switching from high to low to which the ECM responds by driving the fuel richer or leaner.

So I would suggest that the sensor switches voltage from above or below 450mv and as the ECM reads this voltage it drives the fuel richer or leaner

Play on words I suspect but I will go with the manufacturer on this one 

[Coyote]

The O2 sensors are clearly switching sensors. The spend 99.9% of their time in one of two states. The ECM uses them as a crude A2D converter.

[rbabos]

The O2 sensors are clearly switching sensors. The spend 99.9% of their time in one of two states. The ECM uses them as a crude A2D converter.

Any sensor I heated with a torch shows constant voltage. Switching high/low has to come from the ecm but the base voltage comes from the sensor. Don't know how you can claim the sensor itself is a switching senor. What am I missing?
Ron

[Coyote]

I'm not sure how you measured it but it likely needs a wetting voltage. But the sensor is doing the switching.

http://www.boschautoparts.com/oxygensensors/pages/premiumoxygensensors.aspx



edit. Perhaps I'm misunderstanding your statement. What drives the switch is the change in the afr which is controlled by the ECM. The voltage swing from the sensor is driven by the sensor in response.

[rbabos]

I'm not sure how you measured it but it likely needs a wetting voltage. But the sensor is doing the switching.

http://www.boschautoparts.com/oxygensensors/pages/premiumoxygensensors.aspx



edit. Perhaps I'm misunderstanding your statement. What drives the switch is the change in the afr which is controlled by the ECM. The voltage swing from the sensor is driven by the sensor in response.

That's ok. I get misunderstood all the time. Let's go with what you think I said.
Ron

[FLTRI]

Switching sensor does not relate to any switch in the sensor.
All it can do is report voltage.
100% of the switch comes from and caused by the ECM NOT the sensor.
The ECM says too lean and richens the mixture only to find out its to rich and leans the mixture.
So othe switching is actually just voltage crossing over say 450mv but the sensor switches nothing...just the ECM.
Just the way I understand it, BWTFDIK?
Bob

[Coyote]

It's an avalanche sensor. Or switching sensor. When it reads above stoich it goes one way, below it goes the other. That is why Bosch calls it a switching sensor. See my post above.

[ultraswede]

But the sensor is doing the switching.

No it is not!
The ECU is doing the switching.
Read and understand also the text in the link to Bosch.

Standard narrow band type Oxygen Sensors operate between 0 and 1 volts, and are only capable of accurately measuring a stoichiometric air/fuel ratio (e.g. 14.7:1). A richer or leaner condition results in an abrupt voltage change and is only useful for qualitative determination. Modern automobiles use "switch" like sensing at idle and part throttle to make small compensations in fuel delivery to keep the air/fuel ratio near 14.7:1.

A richer or leaner condition results in an abrupt voltage change and is only useful for qualitative determination.

That mean that the 02 sensor is reporting a constant voltage of 0.450 V at stoich combustion.
Anything leaner or richer will result in 1v or close to zero V.

"switch like sensing" from the text above is the strategy used (by the ECU) and mean that the fuel correction shown at the bottom small graph is what is done to achieve the sine wave voltage from the o2 sensor shown on the graph above.

The ECU is doing all the fuel control, not the sensor.
The sensor is forced to switch 0-1-0-1... volt due to the actions of the ECU.

[Scotty]

But the sensor is doing the switching.

No it is not!
The ECU is doing the switching.
Read and understand also the text in the link to Bosch.

Standard narrow band type Oxygen Sensors operate between 0 and 1 volts, and are only capable of accurately measuring a stoichiometric air/fuel ratio (e.g. 14.7:1). A richer or leaner condition results in an abrupt voltage change and is only useful for qualitative determination. Modern automobiles use "switch" like sensing at idle and part throttle to make small compensations in fuel delivery to keep the air/fuel ratio near 14.7:1.

A richer or leaner condition results in an abrupt voltage change and is only useful for qualitative determination.

That mean that the 02 sensor is reporting a constant voltage of 0.450 V at stoich combustion.
Anything leaner or richer will result in 1v or close to zero V.

"switch like sensing" from the text above is the strategy used (by the ECU) and mean that the fuel correction shown at the bottom small graph is what is done to achieve the sine wave voltage from the o2 sensor shown on the graph above.

The ECU is doing all the fuel control, not the sensor.
The sensor is forced to switch 0-1-0-1... volt due to the actions of the ECU.

Yes the ECM does the fuel control based on the voltage it receives from the sensor which SWITCHES from <450mv> depending on how much fuel is added or removed by the ECM

All the sensors do is report a voltage <450mv> and the ECM adds/remnoves the fuel and then polls the sensor to see if switched from <450mv>

Argue all you want that is how I read the Bosch text and understand the Harley ECM and have no trouble tuning............

[FLTRI]

Consider this:
O2 voltage is basically a 0-1v output sensor. Assigning 450mv to as a reference is exactly that.. a reference point used to determine AFR @ ~14.7 for gasoline..
Look at the wave form. Do you see any switching going on?
The sensor does absolutely nothing but generate a voltage.
The 450mv switch is nothing more than a fueling adjustment point. If either higher or lower voltage than the reference point.
If we were to use 600mv in lieu of 450mv would the sensor then switch at 600mv? How 'bout 780mv?
Bob

[Hilly13]

The sensor voltage swings in reaction to 02 content that the ECM has created with its fuelling, the ECM does not monitor the sensor voltage continuously, rather it samples the voltage at a programmed stage of the combustion cycle(switching) to see if the 02 content is where it expects it to be, it adds or subtracts fuel based on that finding + all the other info it is gathering from the other sensors to keep the AFR in check.....well that's how I thought it worked, happy to be corrected as that's what this section is all about.

[Scotty]

Consider this:
O2 voltage is basically a 0-1v output sensor. Assigning 450mv to as a reference is exactly that.. a reference point used to determine AFR @ ~14.7 for gasoline..
Look at the wave form. Do you see any switching going on?
The sensor does absolutely nothing but generate a voltage.
The 450mv switch is nothing more than a fueling adjustment point. If either higher or lower voltage than the reference point.
If we were to use 600mv in lieu of 450mv would the sensor then switch at 600mv? How 'bout 780mv?
Bob

Well Bob you obviously have not read the Bosch documents (or fail to understand them) that your buddy SC used to put up quite regularly.

Bosch designed them and know how they work and call them switching sensors.........good enough for me

Perhaps you should contact Bosch and get them to explain to you why they call them switching sensors as you obviously won't believe anyone here.

[rbabos]

I think switching sensor is more of a term for it's operation rather than the sensor itself. Switching has to come from the ecm or it would just sit there at a constant voltage.
Ron

[wurk_truk]

Bob,..... Scotty, et al, has this correct.  I HAVE read what SC had to say.  There is more than one type of 'switch'.  Most think of a switch as a wall switch, either on, or off.  But in 'controls' work, there is also the threshold of the device the switch is attached to.  It works as a TEAM, just like the light switch controls a ceiling fan.  ALL electronics use threshold amounts of voltage.  There is NO true 'on' and no true 'off'.  There is 'low' and 'high'.  There IS a difference.  There will always be leakage voltage present.  Leakage voltage doesn't matter, what matters is the threshold voltage in the transistor.  This is ALL about how DC current works and how a sensor reports.

There are TWO types of photo eyes for example.  Transistor based or has an actual microswitch inside.  The one with a switch will leak a very small amount of voltage, the transistor based ones WILL leak appreciable amounts of voltage.

ANYTHING that is even loosely transistor based works in this manner.  Our ECM has chips, etc inside, so it also works on 'transistor' theories.  Low and High.  NOT off and on.

This type of switch works like this.  Most think a light bulb attached (or a VOM) to a sensor would see the light go off and on, if it was a switch.  In reality, the light will go really dim, to really bright.  Why?  It is hitting the gate  on the transistor(inside of the ECM) making the 'transistor' turn off and on.  Switching sensors turn on and off the transistor attached.  It is a system and THAT is the why it is called a switching sensor as it 'switches' the attached transistor on and off.  The transistor inside turns on and off.  THAT is where the sensor is reporting... after the attached transistor.  If one could hook up that light bulb to the opposite side of the transistor...  the light WOULD turn on and off.

This IS basic 'controls' theory and is the how all kinds of machines work.  Photo-eyes, proximity switches, etc all work in this manner.  A sensor does NOT live in a vacuum.  It IS what that sensor is hooked up to, to call it a 'switch' or a device that measures voltage (analog voltage device).  A switch looks like the voltage characteristics of a narrow band.  Exactly.  This IS a 'switch' when working with controls, whether they be on a vehicle or a piece of machinery that MAKES the vehicle.  It IS a digital switch.

True voltage representations are the graphs from Wide Bands.  That graph is really quite linear and works on a 0 to 5 volt system.  0 to 1 is a switching voltage.  For the application, it's a switch, because NOTHING is in a vacuum, Ron.  It depends on what it is hooked up to, and THAT (what something is hooked up to) is what is 'termed' a switch or not.

The ECM does NOT throttle around a voltage.  Doesn't.  Wide band controllers do that.  Scotty IS knowledgeable on this subject, BTW.  Our NB sensors ONLY report low and high, and NOT the voltage present.  WHile the ECM 'warbles' the fuel  low to high to low to high (PID Controls)  all it really is doing is going to report low AFR, high AFR, low AFR, etc.  The bias in CLBs etc just alter where the switching point, in the ECM is received at.  It works on PID, so if it reads HIGH when commanded LOW, the ECM compensates fuel delivery to make what IS to what is EXPECTED.

The actual 'switch' is whatever the attached transistor says it is ON or OFF. between the two, the sensor reports to the transistor (the WHOLE 'switch")  and we change THAT voltage... the amount of leak before the transistor 'sees' the voltage to change state.

[wurk_truk]

Yes Ron, you ARE correct!!!!  The ECM warbles the fuel while going down the road.  The sensor reports back lean or rich.  Just those two 'answers'  NOTHING else.  It does NOT read voltage, it IS a digital switch.

The 'switch', by itself is NOTHING.  It would be a light switch WITHOUT that ceiling fan.  It is ALWAYS about the system as a whole.  AND... 'terminology' is ALWAYS based upon the application and not what you or I think.

A few years ago, I stumbled around with this crap and how it works on controls, until I learned how to think about it all.  All of this low/high BS is confusing, until I learned to call the system as a whole the 'actual' switch.  Our O2 sensors, by themselves, do NOT make any kind of switch at all.  Think of this as a 'switch' that has two, separated, components.  Until that transistor inside the ECM, or PLC, or whatever, switches... there is nothing.  On a cheap ass PLC running 24vdc, the switching voltage (from 'on to off') can be as high as 14vdc!  Everything is made to go 'low to high' at a lower voltage as that.

In our application...  it IS a switching function...  simply High to Low.  The sensor, ANY sensor is simply made to react with whatever it is that senses the sensor.  Like the turning on or off a gate in a transistor or chip.

Ron, try this, as I am curious... instead of just heating a NB sensor and measuring voltage, also introduce some oxygen into a chamber.  Weld up an old pipe we could screw a sensor into, along with a bung we could introduce oxygen.  Remember this crap measures the DIFFERENCE in oxygen in the chamber, and without the chamber.  That difference IS the O2, what the sensor reads.

Besides keeping the operator safe... we all like the best fresh air as possible on a dyno, because we wish to have the 'reference' air of the sensor to be CLEAN air, right?

[ToBeFrank]

When it reads above stoich it goes one way, below it goes the other.

You mean, like a switch? 

[ultraswede]

it IS a switching function...  simply High to Low

Yes agree, it could be. BUT it its the ECM that move the AFR up or down, causing the sensor to "switch"
NOT the sensor switching by its own.

IF the sensor is doing the switching, how do you then explain that the switching frequency follow Rpm up or down?
The sensor just sits in the exhaust stream and no nothing about Rpm.

[rbabos]

Yes Ron, you ARE correct!!!!  The ECM warbles the fuel while going down the road.  The sensor reports back lean or rich.  Just those two 'answers'  NOTHING else.  It does NOT read voltage, it IS a digital switch.

The 'switch', by itself is NOTHING.  It would be a light switch WITHOUT that ceiling fan.  It is ALWAYS about the system as a whole.  AND... 'terminology' is ALWAYS based upon the application and not what you or I think.

A few years ago, I stumbled around with this crap and how it works on controls, until I learned how to think about it all.  All of this low/high BS is confusing, until I learned to call the system as a whole the 'actual' switch.  Our O2 sensors, by themselves, do NOT make any kind of switch at all.  Think of this as a 'switch' that has two, separated, components.  Until that transistor inside the ECM, or PLC, or whatever, switches... there is nothing.

In our application...  it IS a switching function...  simply High to Low.  The sensor, ANY sensor is simply made to react with whatever it is that senses the sensor.  Like the turning on or off a gate in a transistor or chip.

Ron, try this, as I am curious... instead of just heating a NB sensor and measuring voltage, also introduce some oxygen into a chamber.  Weld up an old pipe we could screw a sensor into, along with a bung we could introduce oxygen.  Remember this crap measures the DIFFERENCE in oxygen in the chamber, and without the chamber.  That difference IS the O2, what the sensor reads.

Besides keeping the operator safe... we all like the best fresh air as possible on a dyno, because we wish to have the 'reference' air of the sensor to be CLEAN air, right?

Not sure anything would change in this test. There would be no switching going on. Isn't this event (high/low needed to determine what O2 content the sensor sees from a base line clb?
Pretty sure all I would see is the voltage come up to 1mv and stay there with or without additional oxygen.
Ron

[Coyote]

You guys are arguing semantics however the industry correct terminology is that the narrow band O2 sensor is a switching sensor. Without a closed loop system, both the switch and ECM outputs would rail and neither would move.

In this application, the ECM provides the integration of the error signal and loop correction. The sensor provides the error signal, either high or low (switching) depending on O2 content.

When it reads above stoich it goes one way, below it goes the other.

You mean, like a switch? 

[FLTRI]

When it reads above stoich it goes one way, below it goes the other.

You mean, like a switch? 

Yep. Any voltage change can be called a switch.
The misnomer is calling the sensor a switch as in "switching sensor".
Consider this: LSU4 broadband and most all sensors, for that matter, are just as much a switching sensor as a narrow band used for stoich and/or making other decisions based on crossing a line. Ie: heat management. The head sensor acts just like a "switching sensor", right?
Bob

[Coyote]

Widebands are not the same as the provide a substantially linear change of voltage to afr. Narrow band provide a step change.



If you won't believe Bosch when they refer to it as a switching sensor, how about Delphi?

http://delphi.com/manufacturers/auto/sensors/engine-and-transmission/gasoline/mini-switching-oxygen/

[wurk_truk]

Bob Bob Bob, you do NOT get it at all.

You guys are NOT getting it.  a NB sensor is a switch and ALL the ECM detects is the state of the switch.  Forget about what the damn sensor does, it is a TWO part sensor... the sensor AND the transistor inside make for the WHOLE switch.  Once more...  THE SENSOR ITSELF IS NOT THE COMPLETE SWITCH.  You argue semantics and gave no understanding here.  In Electronic controls, it IS the ECM that determines what the activity does.  Why do you guys argue this?

A WB, OTOH, is an analog sensor.  It reads from 0vdc to 5vdc.  This is the WHY there is a damn slope, Guys!  This sensor does NOT go to a transistor, it goes to an analog voltage reading circuit.  It is WHY these devices need a WEGO UEGO, etc.  THAT WEGO is THE controller that converts the WBs signal to 0-5vdc.

NBs are digital and wide bands are analog.  If this all beyond you to understand?  Just take it as a fact.  Inputs on a PLC are the same way.  One can denote, thru software, whether a switch is digital (and on some what voltage is the tipping point), analog READS 0-5vdc and each increment of that system can be programmed for a different result.

You guys THINKING a switching sensor is an analog sensor does NOT make it so.

I give up now.  It is simply beyond your level of expertise.  I recommend reading on analog switching and digital switching on the internet.  ANd NOT revolving around O2 sensors.  You need a background to this.

Our ECM does NOT 'read' and react on the voltages of the NB switches.  It is simply a go/ no go device.  We DO set the point of go or no go, but ALL it friggin reads is either lean or rich.  It is a switch.  CLB IS the tipping point of the switch.  We alter the tipping point of the transistor to alter what is nominal voltage.

A WB with controller will read HOW rich and HOW lean the O2 concentration of the gas really is.  HUGE difference between the two.

If you ARE having problems with this...  you do NOT understand exactly HOW a PID circuit works.

Like me with certain mechanical stuff.  I need to ask and listen, you guys ask, don't accept the answers and argue instead.

Done.
Sensors 101.

[rbabos]

I found this, and it starts to make sense even for a retard like me. Plus John won't need to yell at me any more.
http://www.autoshop101.com/forms/h37.pdf
Covers how 02 effects the voltage and what play the ecm has in the picture. Yes it is a switching sensor.
Ron

[wurk_truk]

NOT yelling nat you... today.  Yelling at BOB,

[Hilly13]

It is either above or below 450mv ie on or or off ...clb changes where the "450" sits.....got it. yeh?

[wolf_59]

Here is a shot from a Vtune cut down to 10 seconds, clb set @ 450 notice the O2 sensor mv being driven rich to lean from around 700 to 40 nothing constant always moving up or down also injector BPW coincides with it (easier to see if not blown up so much) but appears the BPW increases and then the sensor shows richer then BPW decreases and sensors mv begins to drop.


[attachment removed after 60 days by system]

[Jeffd]

Bob Bob Bob, you do NOT get it at all.

You guys are NOT getting it.  a NB sensor is a switch and ALL the ECM detects is the state of the switch.  Forget about what the damn sensor does, it is a TWO part sensor... the sensor AND the transistor inside make for the WHOLE switch.  Once more...  THE SENSOR ITSELF IS NOT THE COMPLETE SWITCH.  You argue semantics and gave no understanding here.  In Electronic controls, it IS the ECM that determines what the activity does.  Why do you guys argue this?

A WB, OTOH, is an analog sensor.  It reads from 0vdc to 5vdc.  This is the WHY there is a damn slope, Guys!  This sensor does NOT go to a transistor, it goes to an analog voltage reading circuit.  It is WHY these devices need a WEGO UEGO, etc.  THAT WEGO is THE controller that converts the WBs signal to 0-5vdc.

NBs are digital and wide bands are analog.  If this all beyond you to understand?  Just take it as a fact.  Inputs on a PLC are the same way.  One can denote, thru software, whether a switch is digital (and on some what voltage is the tipping point), analog READS 0-5vdc and each increment of that system can be programmed for a different result.

You guys THINKING a switching sensor is an analog sensor does NOT make it so.

I give up now.  It is simply beyond your level of expertise.  I recommend reading on analog switching and digital switching on the internet.  ANd NOT revolving around O2 sensors.  You need a background to this.

Our ECM does NOT 'read' and react on the voltages of the NB switches.  It is simply a go/ no go device.  We DO set the point of go or no go, but ALL it friggin reads is either lean or rich.  It is a switch.  CLB IS the tipping point of the switch.  We alter the tipping point of the transistor to alter what is nominal voltage.

A WB with controller will read HOW rich and HOW lean the O2 concentration of the gas really is.  HUGE difference between the two.

If you ARE having problems with this...  you do NOT understand exactly HOW a PID circuit works.

Like me with certain mechanical stuff.  I need to ask and listen, you guys ask, don't accept the answers and argue instead.

Done.
Sensors 101.

a rose is a rose.  You explained it well.

[wurk_truk]

It is either above or below 450mv ie on or or off ...clb changes where the "450" sits.....got it. yeh?

Yes Hilly.  And our CLB simply alters that 450mv switching point and nothing else.

YOU are MY Dude!

[Hilly13]

Wurk  cheers

[FLTRI]

NOT yelling nat you... today.  Yelling at BOB,

No need to YELL!
In the early days before wide bands we would send the exhaust system and narrow bands ("switching") sensors to the engine builder. He would dial in the best performance mixture on the engine Dyno to...say 12.8:1. Then take the reading from the o2 sensor (usually ~870-890mv IIRC). Then we monitored the sensor output and readjusted fueling to keep within that voltage target.
Was it perfect? No but,it was certainly better than trying to read plugs after idling back into the pits. Lol
Sorry if I don't see anywhere in or on the sensor a switch...just a voltage output that the ECM then switches the fueling to either richer or leaner than the reference point.
I have no theory of operation or a plethora of technical terms to back up my personal observations.
My only experience is from actually using these sensors for other than a switch from Stoich.
Please take a moment to take another look at the sine wave (not square wave) Bosch graph of the "switching" sensor Coyote offered. That does not appear to be switching anything just reporting voltage increases and decreases as the ECM commands fueling changes.
Bob
PS- Yelling and personal digs and insults will not change the fact these narrow band sensors have no switching ability whatsoever...just variable voltage output...it is the ECM that switches.

[rbabos]

NOT yelling nat you... today.  Yelling at BOB,

No need to YELL!
In the early days before wide bands we would send the exhaust system and narrow bands ("switching") sensors to the engine builder. He would dial in the best performance mixture on the engine Dyno to...say 12.8:1. Then take the reading from the o2 sensor (usually ~870-890mv IIRC). Then we monitored the sensor output and readjusted fueling to keep within that voltage target.
Was it perfect? No but,it was certainly better than trying to read plugs after idling back into the pits. Lol
Sorry if I don't see anywhere in or on the sensor a switch...just a voltage output that the ECM then switches the fueling to either richer or leaner than the reference point.
I have no theory of operation or a plethora of technical terms to back up my personal observations.
My only experience is from actually using these sensors for other than a switch from Stoich.
Please take a moment to take another look at the sine wave (not square wave) Bosch graph of the "switching" sensor Coyote offered. That does not appear to be switching anything just reporting voltage increases and decreases as the ECM commands fueling changes.
Bob
PS- Yelling and personal digs and insults will not change the fact these narrow band sensors have no switching ability whatsoever...just variable voltage output...it is the ECM that switches.

Didn't read my link , did you? Explains it well.
Ron

[wurk_truk]

HAHAHAHA!!!!!

[Coyote]

Bob, you are correct in saying that the narrow band devices don't actually switch (as in digital on or off). They are still an analog sensor but their response profile is of an avalanche type which makes them a switching sensor. I'm not at all sure how Delphi does their closed loop but all closed loop systems have the same blocks that integrate the feedback, set the loop frequency, loop response and reference.

I would guess that Delphi reads the sensor voltage and calculates (by integration) the area under the curve for both positive and negative areas around a fixed point (the 450mV usually). I believe that it is more complex than just saying it's rich or lean based on a sample of the sensor at any given time. The formulas for calculating loop dynamics are involved. I know as I have been designing closed loop systems for the last 25+ years.

I suspect we may have one or maybe two on the site that know details of how Delphi did this but I'm not one of them. I just understand closed loop design having done it for so long (albeit a different application).

[wolf_59]

Read page 3 under operation on the link from Ron
"From the oxygen content the ECM can determine if the air/fuel ratio is rich or lean and adjust the fuel mixture accordingly."
And on page 4 the diagram shows the narrow window that the O2 sensors are able to work in and states " the ECM will continuously add and subtract fuel producing a rich/lean cycle."

[FLTRI]

From the document rbabos offered:
"Think of them as switching sensors."
My ONLY point was that these sensors have no switching ability...again...just a voltage output that will provide reliable AFR control around the 450mv.area.
Outside that reliable area all bets are off (hence "narrow bands"?).
That is why we tried to pinpoint just 1 voltage output as it related to target AFR ie:12.8. While we were way outside the reliable range we calibrated each sensor voltage output that produced the desired 12.8 AFR. Each sensor was individually calibrated to what voltage = 12.8 AFR. That was in "early" days  of D/A systems designed for racing applications.
As always JMHO,
Bob

[FLTRI]

It's alright to be wrong Bob just man up and admit it.

it's amazing how you claim that you know more than Bosch but when someone claims to know more than TTS you get all defensive.

Absolutely amazing isn't it? How this is really a personal issue isn't it? I've never made any claim to know more than anyone...just relate my own personal experiences.
What are some of your personal tuning experiences using these sensors?
Do you see where these sensors fail to provide a smooth running Harley if the sampling is reliable in the pipe?

A switch does not need to be on/off it can be up/down, left/right, decrease/increase, +5-5

Yes you call anything that changes, a switch. My only point was that the sensor is not a physical switch in any way.

Bob

[Scotty]

It's alright to be wrong Bob just man up and admit it.

it's amazing how you claim that you know more than Bosch but when someone claims to know more than TTS you get all defensive.

Absolutely amazing isn't it? How this is really a personal issue isn't it? I've never made any claim to know more than anyone...just relate my own personal experiences.
What are some of your personal tuning experiences using these sensors?
Do you see where these sensors fail to provide a smooth running Harley if the sampling is reliable in the pipe?

A switch does not need to be on/off it can be up/down, left/right, decrease/increase, +5-5

Yes you call anything that changes, a switch. My only point was that the sensor is not a physical switch in any way.

Bob

Yes it is a switching sensor and I have more faith in Bosch's description and technical expertise than yours.

Don't take it personally when your wrong just admit it and move on to the next subject like I'm going to do as this thread is about 1 message away from being locked.

[joe_lyons]

Do the heated o2 sensors heat when on decell, bc every time I decell they cool off then when I get back on it they respond again or is that just my sensor location?

[ultraswede]

If we feed the o2 sensor a CONSTANT stoic AFR, as in a heated calibration gas, the output will be 0,450 V.


Can we agree on that?

[hpulven]

Interesting discussion between many knowledgeable persons here,
and I find it a bit puzzling that there is disagreement about
this, but I suppose it all comes down to semantics.

I would say: The nb o2 sensor is an anologe sensor.

(Be aware; I am talking about the sensor, not motorcycles,
engines, ecm,  only the device in itself, it might
theoretically be used for other things...)

A sensor is a device that outputs a signal as a response to
some observed physical condition it is monitoring.

A signal is digital if it can only output a limited set of
discrete values on a noncontinous, discrete scale.
(Normally binary digital, like ___--__-_---_-_-,
for example only 0 or 5 volts.)

A signal is analoge if it can be every value on a
continous scale, let us say everything between
0 and 1 volt.

Someone has to explain to me how these definitions of
sensor, analoge and digital can be used to say the
nb sensor is a digital switching sensor.

That the ecm is treating it as a digital sensor,
and that Bosch and Toyota say we should <i>think</i>
about it as a switch,
does not change the fact that the sensor in itself
is an analoge device.

Another thing; <i>is</i> the ecm really treating the
nb sensor as a digital switch, I don't know, but
I would have thought the ecm was more advanced than that,
not only registering if the sensor is over or under
a switching point, but also how much it is over or
under the switching point.

And, one more thing; some say the ecm is behaving
like a PID controller, that is not entirely true
either,is it? A PID controller would normally
try to stabilize the output from the sensor on
the target level, the ecm is doing something else,
it is driving the system to oscillate around the
target level, which takes another algorithm than
what is usually used in a PID. The only reason
for this is to be nice to the catalytic converter,
which most of you probably ripped out in the
first place. I am not saying this to start a new
quarrel, it just occured to me that some of
the third party ecm producers should make an ecm that
behaved like a real PID controller for the
majority of bikes where being nice to the
catalytic converter is of no interest whatsoever...
just a thought :-)

[strokerjlk]

Bob, you are correct in saying that the narrow band devices don't actually switch (as in digital on or off). They are still an analog sensor but their response profile is of an avalanche type which makes them a switching sensor. I'm not at all sure how Delphi does their closed loop but all closed loop systems have the same blocks that integrate the feedback, set the loop frequency, loop response and reference.

I would guess that Delphi reads the sensor voltage and calculates (by integration) the area under the curve for both positive and negative areas around a fixed point (the 450mV usually). I believe that it is more complex than just saying it's rich or lean based on a sample of the sensor at any given time. The formulas for calculating loop dynamics are involved. I know as I have been designing closed loop systems for the last 25+ years.

I suspect we may have one or maybe two on the site that know details of how Delphi did this but I'm not one of them. I just understand closed loop design having done it for so long (albeit a different application).

my experience is with Red Lion.
based on the tuning software we use to tune red lion controllers. I ask in your opinion...is the delphi strategy a true PID system? or is it missing derivative? and therefore actually a PI controller in a sense?

[strokerjlk]

Interesting discussion between many knowledgeable persons here,
and I find it a bit puzzling that there is disagreement about
this, but I suppose it all comes down to semantics.

I would say: The nb o2 sensor is an anologe sensor.

(Be aware; I am talking about the sensor, not motorcycles,
engines, ecm,  only the device in itself, it might
theoretically be used for other things...)

A sensor is a device that outputs a signal as a response to
some observed physical condition it is monitoring.

A signal is digital if it can only output a limited set of
discrete values on a noncontinous, discrete scale.
(Normally binary digital, like ___--__-_---_-_-,
for example only 0 or 5 volts.)

A signal is analoge if it can be every value on a
continous scale, let us say everything between
0 and 1 volt.

Someone has to explain to me how these definitions of
sensor, analoge and digital can be used to say the
nb sensor is a digital switching sensor.

That the ecm is treating it as a digital sensor,
and that Bosch and Toyota say we should <i>think</i>
about it as a switch,
does not change the fact that the sensor in itself
is an analoge device.

Another thing; <i>is</i> the ecm really treating the
nb sensor as a digital switch, I don't know, but
I would have thought the ecm was more advanced than that,
not only registering if the sensor is over or under
a switching point, but also how much it is over or
under the switching point.

And, one more thing; some say the ecm is behaving
like a PID controller, that is not entirely true
either,is it? A PID controller would normally
try to stabilize the output from the sensor on
the target level, the ecm is doing something else,
it is driving the system to oscillate around the
target level, which takes another algorithm than
what is usually used in a PID. The only reason
for this is to be nice to the catalytic converter,
which most of you probably ripped out in the
first place. I am not saying this to start a new
quarrel, it just occured to me that some of
the third party ecm producers should make an ecm that
behaved like a real PID controller for the
majority of bikes where being nice to the
catalytic converter is of no interest whatsoever...
just a thought :-)

[/color]
I missed your post first time through   Good points.

[rbabos]

Do the heated o2 sensors heat when on decell, bc every time I decell they cool off then when I get back on it they respond again or is that just my sensor location?

I thought they heat full time. Maybe extra decel fuel cools them off.
Ron

[FLTRI]

Do the heated o2 sensors heat when on decell, bc every time I decell they cool off then when I get back on it they respond again or is that just my sensor location?

I thought they heat full time. Maybe extra decel fuel cools them off.
Ron

My weak unprofessional and ignorant understanding is the O2 sensors are not heated all the time. The ECM determins when the heater is necessary and not.
During decel the exhaust, depending on design of course, pulls cold are into the exhaust, right?
That cold air cools the sensor which can take it offline temporarily. Since decel usually doesn't last very long the sensor will come back online soon, almost instantly, after load is returned to the engine.
Just some more of my ignorance showing through,
Bob

[joe_lyons]

I was just wondering BC even if I do a long decell from 6k to idle they stay off line the whole time.  Not a big deal just wondering. And I am pretty sure they are not heated all of the time just when deemed needed

[rbabos]

Do the heated o2 sensors heat when on decell, bc every time I decell they cool off then when I get back on it they respond again or is that just my sensor location?

I thought they heat full time. Maybe extra decel fuel cools them off.
Ron

My weak unprofessional and ignorant understanding is the O2 sensors are not heated all the time. The ECM determins when the heater is necessary and not.
During decel the exhaust, depending on design of course, pulls cold are into the exhaust, right?
That cold air cools the sensor which can take it offline temporarily. Since decel usually doesn't last very long the sensor will come back online soon, almost instantly, after load is returned to the engine.
Just some more of my ignorance showing through,
Bob

Ok, so where's your data to support this. To be switched on and off with the time delay for heat it wouldn't make sense. It would seem to be on full time, EPA wise the heat in the sensor would cause less time outs. Just trying to learn.
Ron

[FSG]

Having just designed and built some O2 Simulators for use in an Automotive application I can say that the Heaters are on full time.

There is no reason to think that a HD would do otherwise, nor is there any documentation, text or wiring diagram that would support one to think otherwise.

The foolproof way to verify it of course is to put a VOM across the 2 Heater wires and monitor the voltage to see if it disappears for periods of time.  Something easy for a Dyno Operator to do.

[HV]

I was out a few weeks ago doing a few Auto tune runs with my PV... now I must say it was COLD ..like 30F ...and I have an X Pipe so there is no Cat to retain built up heat close to the Heated sensors...watching he Monitor I could see them going off line after I slowed to a stop and I had to ride for a few feet under a load before they came back on line ...even moving slow in traffic would not bring them back up ....now today I did the same run with a 40   F day and they were active almost all the time

[rbabos]

Having just designed and built some O2 Simulators for use in an Automotive application I can say that the Heaters are on full time.

There is no reason to think that a HD would do otherwise, nor is there any documentation, text or wiring diagram that would support one to think otherwise.

The foolproof way to verify it of course is to put a VOM across the 2 Heater wires and monitor the voltage to see if it disappears for periods of time.  Something easy for a Dyno Operator to do.

Thanks for the info.  It would seem this would be the best way to use them. On and off would seem to be counter productive for their intended purpose.
Ron

[joe_lyons]

So my decell is enough to cool them off too much so the heaters cant keep up with heating them.  I do know in the Delphi literature it says it can go up to 1 amp to light them off quick.  So possibly a variable heater amperage per the situation.

[rbabos]

So my decell is enough to cool them off too much so the heaters cant keep up with heating them.  I do know in the Delphi literature it says it can go up to 1 amp to light them off quick.  So possibly a variable heater amperage per the situation.

I've not found any info other than they heat full time. Delphi lit does say sensor life dramatically reduces if heater function fails or degrades.
Ron

[FSG]

Just wait until HD is forced to follow the Auto Industry with the addition of an O2 Sensor(s) after the Cat so the ECU can monitor the performance of the Cat and throw codes or go into limp mode as it's sees fit.  Then there will be a market for O2 Simulators once again.

[joe_lyons]

Or we will have an option to turn them of in our tunning devices.

[rbabos]

Or we will have an option to turn them of in our tunning devices.

There you go. Problem solved.
Ron

[FSG]

True, but do you think that Tuning Mfrs would want to skate on that thin ice, that is if the're not on it already.   

[joe_lyons]

Its all off road use so its OK.

[rbabos]

True, but do you think that Tuning Mfrs would want to skate on that thin ice, that is if the're not on it already.   

I think I've pushed that accept the offroad button use a few times today.
Ron

[wurk_truk]

I think that the heaters DO, in fact oscillate.  Why else having a 'heater circuit' and not an on off with a key on?

What CAN be happening, I have NO clue but logic here, that maybe the controller varies the amperage? Like Joe suggests.  amperage could be used as an equal method as volts to warble a heater.

I DO know that a heater, if unplugged, throws a code in a car.  That being the case....  that logic tells me SOMETHING is being monitored.  A heated metal will have less impedance, as compared to a cold metal, especially some weird kind of bimetallic.

Google?

[rbabos]

I think that the heaters DO, in fact oscillate.  Why else having a 'heater circuit' and not an on off with a key on?

What CAN be happening, I have NO clue but logic here, that maybe the controller varies the amperage? Like Joe suggests.  amperage could be used as an equal method as volts to warble a heater.

I DO know that a heater, if unplugged, throws a code in a car.  That being the case....  that logic tells me SOMETHING is being monitored.  A heated metal will have less impedance, as compared to a cold metal, especially some weird kind of bimetallic.

Google?

One way to find out. Slap a multi on the heater wire to ground and see if it remains constant. My money is it will. Throwing a code is why PV has an O2 heater on/ off switch. It prevents the ecm from throwing a code when deactivated in the software.
Ron

[wurk_truk]

Would need an amprobe to find this out, NOT a VOM without that, and one that works >1 amp ranges is NOT in my tool box.

Also, one must be very careful on what ground they attach a probe to.  It MUST be the same ground as used by the ECM...  we call them clean grounds.  Or... you introduce the potential between the two grounds into the equations. There IS a need to be careful.

The controller works by varying how much grounding takes place, NOT whether the 'hot' side changes voltage.  It is the GROUND side that changes in these systems.

What some miss is... the 'heater plus" will ALWAYS be hot AND at the same voltage.  Just like an O2 sensor circuit.  Look at the circuits on a schematic.  Hots are shared, and grounds come back to the ECM separated.

So... what is TRULY needed is to find an unused 5vdc GROUND off of the ECM and see if there is a potential as compared to the heater grounds.

Don't wish to toast something with very small voltages, etc, THRU a meter probe.

I will get my scope back and see if that can be used for amps.

[rbabos]

Would need an amprobe to find this out, NOT a VOM without that, and one that works >1 amp ranges is NOT in my tool box.

Also, one must be very careful on what ground they attach a probe to.  It MUST be the same ground as used by the ECM...  we call them clean grounds.  Or... you introduce the potential between the two grounds into the equations. There IS a need to be careful.

The controller works by varying how much grounding takes place, NOT whether the 'hot' side changes voltage.  It is the GROUND side that changes in these systems.

What some miss is... the 'heater plus" will ALWAYS be hot AND at the same voltage.  Just like an O2 sensor circuit.  Look at the circuits on a schematic.  Hots are shared, and grounds come back to the ECM separated.

So... what is TRULY needed is to find an unused 5vdc GROUND off of the ECM and see if there is a potential as compared to the heater grounds.

Don't wish to toast something with very small voltages, etc, THRU a meter probe.

I will get my scope back and see if that can be used for amps.

Theres a test procedure in the link I posted yesterday . It shows ground as the control, just like you say.
Ron

[ToBeFrank]

A PID controller would normally
try to stabilize the output from the sensor on
the target level, the ecm is doing something else,
it is driving the system to oscillate around the
target level

The sensor response it too sensitive. It will never "stabilize" on a running engine. That's why it oscillates from the PID control. Yes, it is PID control. I put stabilize in quotes because oscillating around a target value is, in fact, stabilized.

[Coyote]

   Its actually the loop response error. All
Closed loop systems have an error, some greater or lesser. It depends on the designed loop response and damping factor.

[FSG]

Obviously the ECM monitors the current flow through the heater for diagnosis purposes, throwing a code if it detects that the  current is above or below a specified range.  While it's possible, I doubt the ECM is varying the current to the heaters so as to control their temperature.

[FLTRI]

Ok got it. Now how can we apply this information to improve O2 sensor performance and lessen deterioration of closed loop feedback?
Thanks for your patience,
Bob