O2 sensors differences, pros and cons

[1FSTRK]

HV this is a sticky topic if ever there was one. If not by itself then maybe add to the
“Be Carefull with the new small heated 02s when installing new pipes”
and amend the title line to O2 warnings, differences, pros and cons.

Please post questions, answers, opinions, and relevant links to O2 sensors. I feel that we have already posted a ton of info and links in other threads that should be here. We can keep individual threads clean and to the point by just reference this thread if we feel the O2 characteristics come in to play. It would also make a quick easy place for a new comer to get up to speed as well as a quick reference for everyone else. Some good points are made and then dropped in other places because they begin to run off the subject of the original thread while other things have been stated 20 times. 
 
This is an important subject to be considered when picking a tuning device as it often will dictate the systems range of self tuning as well as a potential reliability or maintenance issue.

Does anyone know the average life in miles of a stock HD sensor?
Does anyone know the average life in miles of a LSU4 when used on a Harley?

Maybe we can gather some info here for a database.
We have a powerful tool in this forum let’s continue to improve it.

[ultraswede]

The usefull life of the stock o2 sensors is 30 000 km or 5 years, whichever occurs first.

Source;
http://www.epa.gov/otaq/regs/roadbike/420f03046.pdf
page 2;
What does the term “useful life” mean?
EPA uses the term “useful life” to describe the period (usually years and/
or miles) over which the manufacturer must demonstrate the effectiveness
of the emission control system. The current useful life for motorcycles
with engines over 279cc is 5 years or 30,000 kilometers (about
18,640 miles), whichever first occurs.

If the actual useful life is longer I don't know, but it is a very short mandatory lifespan stipulated above.
It seems logical that the Mo-Co don't engineer anything to last longer than necessary, i.e 30 000 km.

[1FSTRK]

Thanks ultraswede

That brings up a thought. Because the factory doesn't install the other sensors trying to nail down an accurate number on how many miles they will last on the average Harley will be up to the public to log and post here unless someone has done actual endurance testing on harleys and can post it.

[FBRR]

The O2 sensors used in "cars" have to last longer than 30k. The big issue with all O2 sensor as they age is response time. The amount of time an O2 sensor switches from RICH to LEAN and LEAN to RICH changes over time. That "aging" time lag change must be taken into account when the emissions are developed. When I did those calibrations the way it was done is we had a "new" system of converters and O2 sensors, and also many sets of "AGED" hardware that had been aged to 150k miles. Emissions standards also are slightly different with miles. ( EPA allow some degradation with miles)
The emissions must still be met as the system ages.

What that means is the "lifespan" of an O2 sensor may not meet emissions requirements becasue of those changes in response times, but from a "PRACTICAL" pont of view, the aged sensor can still work for closed loop fuel control after even longer than the "stated lifespan." ( They may just not continue to be able to meet "emissions" requirement)

So as a caution, there is a difference between a O2 sensor "LIFE" where the O2 sensor no longer FUNCTIONS and the point where they simply no longer meet "emission standards." The OEM stated "life span" obviously is based on meeting emissions! Not absolute from a FUNCTION standpoint!
( I should add the O2 sensor "life" is a function of operating temperature. So one person that rides easy might get twice as much useful life from an O2 sensor as someone that rides HARD. Contamination is also a major "killer" of O2 sensors. Some things that can poision a sensor are "oiled air filters" that are over oiled as well as engines that have an "oil consumpsion"issue!)

[Steve Cole]

Here is a good link for as long as it last, you can however download and save a copy of it.

http://www.bosch.com.au/content/language1/downloads/Oxgen_Sensor__Cat_WEB.pdf

On pages D4 and D5 it shows how Bosch recommends to mount the O2 sensor and how to make the bung you mount it in. D4 also shows a drawing of proper placement in the pipe on the lower left side. You can also read about exceptions to there suggestions on D5. Then on page D8 - D11 is the section on the LSU 4.2 sensor.

All I can tell you is that we see a much higher failure rate reported back from the field on LSU sensors then we do on the stock OEM sensor. There does not seem to be a pattern on a specific combination that most the failures occur on and seems to be an even mix across different builds. We have seen these same type of failure rates in the automotive industry for a long time when trying to use this sensor (LSU) as a tuning sensor. In the automotive world these were being sold as the newest thing back 10 years ago. Since then most everyone has learned better. While it will get you close at a wider range than an OEM switching sensor it just doesn't hold up longer term. Many race teams have learned over the years to use them for tuning then remove them due to these failures or step up and buy a true Wide Band sensor system. The typical failure mode on a LSU sensor is to begin to drift away from a close reading to one that can be off as much as +/- 1.0 AFR then shortly after they have drifted that far they will completely die. So the big issue comes from the drift of the sensor feeding wrong information back to the ECM to correct from. Since the ECM does not know any better it begins making corrections to bad data.

Things that kill any O2 sensor range from too much heat, oil in the exhaust, improper placement and anything that allows lead into the fuel.

[1FSTRK]

Thanks to both FBRR and Steve for excellent info from both.

 

[1FSTRK]

I can see that because of the wideband sensor’s ability to correct from a larger range of error that at first glance it sounds like the good choice. Disregarding the replacement cost and frequency, which I would have to factor in after I see how long they last on each particular bike and the way I ride it, could I assume that a bike tuned in this fashion would show me a measurable fuel mileage change that could be used to alert me to have the sensors checked?

[Steve Cole]

The mileage is going to be set by whomever tuned it and how it gets ridden. The sensor has little to do with it other than correcting for changes down the road. So if they set you up rich 14 cruise and 12.5 WOT you can expect less mileage than if they set you up at 14.5 cruise and 13.2 WOT. This of coarse assumes that both tuneup's have done the spark correctly. All one can do is hope they notice any change after the tune and pay attention to those changes, to make a decision from.

[ultraswede]

could I assume that a bike tuned in this fashion would show me a measurable fuel mileage change that could be used to alert me to have the sensors checked?

I don't think so, a change of 1 AFR due to sensor drift could spell "melted pistons" if the motor drifts lean in a high performance application. In such a situation (hi- perf) you would propably not monitor MPG.

In a touring example relating to the above, riding at 90-100 mph a whole tank full,
what would happen if the AFR went from 14.5 to 15.5?......

[1FSTRK]

I think Steve may have misunderstood me, Ultra maybe on the right track.

My example assumes the bike has been running without issue and I am on a regular riding schedule. I always check my mileage after a fill up, it comes from years of iron sportsters with 2 gal tanks and only a speedometer between riding and walking. I'm riding along getting 45-47 mpg on a regular basis and suddenly it changes. This would tell me something is up and then I could check my sensors. I change out the bad one and go back to my previous mileage. Is this a reasonable scenario?
Now that I think of it wouldn't this be the same no matter which sensor is used?
I guess the questions would be:

When the sensor degrades to the point that it is a problem would it show up in carefully monitored gas mileage?

Is there a difference in the two sensors types in the amount of time between when the degradation becomes a problem and when it totally quits? “Will one linger on for a longer time before quitting?”

[Steve Cole]

The Delphi ECM has limits set in it to flag when the switching sensor it operating properly. So it will run in open loop as a default. Since it's range is much narrower (14.4- 16.8:1)than a wide band or broad band it works. Now let's go to a real Wide band, anything in the range of 4:1 to 25.5:1 is good so if you set a test up around that anywhere in between that is also good. Broad Band sensor (LSU 4) have a range of about 10.2 - 25.5:1 so anything with in that range has to be OK as well. 10.2:1 will kill mileage and possibly cause oil consumption, while 25.5:1 will melt parts as Ultra stated.

So the next question has to be can I limit the range I allow the system to adjust, yes it can be done, but then why have something that can read a larger range installed? Look there will always be Pro's and Cons to whatever gets done. You just have to pick one and live with it. IMHO the Con's on the Broad Bands keep me away from them.

[1FSTRK]

Back to the sensors themselves. With in their individual ranges in the accuracy of both sensors the same?

What is the useable range of each AFR wise?

[ultraswede]

I only know (a fraction ) of how the NB sensors operate.

This pretty much tells the story on the OE sensors;
From Bosch, inventors of the Lambda sond.


Extremely accurate over an extremely narrow AFR range.

Here is the data of a Wide band sensor:


Read more at :
http://www.bosch-lambdasonde.de/en/lambdasonde_funktion.htm

[1FSTRK]

Thanks

[Steve Cole]

When using Broad Band sensors from Bosch in order to get the accuracy they call out you must MEASURE and correct for temperature of the exhaust and pressure in the exhaust at the same time you take the reading from the sensors.

[FSG]

Here is a good link for as long as it last, you can however download and save a copy of it.

http://www.bosch.com.au/content/language1/downloads/Oxgen_Sensor__Cat_WEB.pdf

and if it doesn't last =>  2009-2010 Oxygen Sensor Cat

[1FSTRK]

When using Broad Band sensors from Bosch in order to get the accuracy they call out you must MEASURE and correct for temperature of the exhaust and pressure in the exhaust at the same time you take the reading from the sensors.

Do narrow bands take pressure and temp in to account?

[BVHOG]

A ton of info on this site regarding the broad band sensors  http://www.daytona-sensors.com/tech_wego.html

[Steve Cole]

The correction needed at or near Stoich is none. As you go further from stoich the errors/corrections get larger and larger. As such you do not have to worry about it with switching sensors.

[Jamie Long]

Both sensors have their place as very effective tuning tools. It all depends on your tuning requirements as well as the tuning product you are using. Both sensors can be effective when used for their intended applications, meaning not just by Bosch or NTK recommendations but by the companies and manufacturers that have tested and incorporated them into their end products. As for aftermarket tuning. as a whole you would have a tough time finding a modern air/fuel tuning device that uses a narrowband sensor (again aftermarket, non OEM), while there are many companies that offer wideband based equipment. When I was at SEMA in November I talked with over a dozen NEW companies now offering wideband tuning applications, this does not include the many already on the market, some of them coming on 10 years. It is also worth mentioning that Wideband sensors are being used more and more in OEM automotive applications, nearly every OE is now using them on core models like the Ford F150. We are seeying more uses and applications for these sensors adopted every day. As far as our experience, we have been tuning with wideband sensors on a Dynojet dyno since 2003 and have used them with a wide range of other products including Thundermax AT, Dynojet PC-V AT, and others and although we have seen some minor issues over the years we have seen very few actual sensor failures. We have sold literally thousands of these products that use the LSU sensor, we support them, we warranty them, and issues are far less than some would lead you to believe

[1FSTRK]

I can see that while using the broad band  in its outer limits to zero in on the tune that the temp and pressure offsets may come into play but in most Harley applications this would seem to be a very short amount of time while the map is being generated. It seems that once its operating in the narrow running range on the tuned map the temp and pressure should have little more effect than on a narrow band sensor.   

[revperf]

Great posts Jamie and FSTRK.

Brian

[TXP]

"When I was at SEMA in November I talked with over a dozen NEW companies now offering wideband tuning applications, this does not include the many already on the market, some of them coming on 10 years. It is also worth mentioning that Wideband sensors are being used more and more in OEM automotive applications, nearly every OE is now using them on core models like the Ford F150."

No doubt about OEM's using widebands in their systems. This has been the case for years. But on which OEM product, the F 150 or any other, is the LSU4.2 sensor used in a primary AFR command role? Correct me if I am misinformed on this, but as far as I know all the automotive OEM's who use this sensor use it in a backup role for emmissions purposes, not a primary AFR command role. What is the reason for this?

[strokerjlk]

Both sensors have their place as very effective tuning tools. It all depends on your tuning requirements as well as the tuning product you are using. Both sensors can be effective when used for their intended applications, meaning not just by Bosch or NTK recommendations but by the companies and manufacturers that have tested and incorporated them into their end products. As for aftermarket tuning. as a whole you would have a tough time finding a modern air/fuel tuning device that uses a narrowband sensor (again aftermarket, non OEM), while there are many companies that offer wideband based equipment. When I was at SEMA in November I talked with over a dozen NEW companies now offering wideband tuning applications, this does not include the many already on the market, some of them coming on 10 years. It is also worth mentioning that Wideband sensors are being used more and more in OEM automotive applications, nearly every OE is now using them on core models like the Ford F150. We are seeying more uses and applications for these sensors adopted every day. As far as our experience, we have been tuning with wideband sensors on a Dynojet dyno since 2003 and have used them with a wide range of other products including Thundermax AT, Dynojet PC-V AT, and others and although we have seen some minor issues over the years we have seen very few actual sensor failures. We have sold literally thousands of these products that use the LSU sensor, we support them, we warranty them, and issues are far less than some would lead you to believe

Jamie  good stuff

[Jamie Long]

No doubt about OEM's using widebands in their systems. This has been the case for years. But on which OEM product, the F 150 or any other, is the LSU4.2 sensor used in a primary AFR command role? Correct me if I am misinformed on this, but as far as I know all the automotive OEM's who use this sensor use it in a backup role for emmissions purposes, not a primary AFR command role. What is the reason for this?

Regardless if the sensors are WB or NB they are not used in a primary command role, as this is the function of the ECM/ECU. The sensors are used as a control function. The primary reason for using the wideband is for their ability to provide feedback over a broader range, this is useful not only for mixtures richer than stoich but also leaner in applications required. This would apply to emissions purposes as well