Any danger of engine damage running with the O2 sensor disconnected?

[x1rider]

After trying 3 Oxygen sensors, putting 2 new injectors in, new head temperature sensor, flashing the ECM with the Race ECM program, testing the wiring resistance, O2 sensor ground, buying a Race ECM from Erik Buell Racing, trying 2 more Race ECM eeproms from xopti, I came to one conclusion. My 2002 X1W runs well only with the O2 sensor disconnected. I tried checking off the "open loop learn enable" function, locking the low AFV limit to 100% (it still goes down to 95%), nothing worked, I get sputtering and spitting through the intake at a constant load (ie. cruising) between 2500-3500RPM. The AFV goes down to the 70% range at time, and my spark plugs are bone white (and the inside of my right leg is getting pretty crispy).
I give up.

With the O2 sensor disconnected, the bike runs just fine, even in the 2500-3500RPM range and my plugs are dark, perhaps even a tiny bit on the rich side (which I'd rather have than the snow white ones I've been seeing for the last 2 weeks).

My question is, is there any risk of engine damage running with the O2 sensor disconnected, or is there a way to "electronically" silence it so I don't have to look at that stupid check engine light.
If there is a risk of damage, my next step is putting my PowerCommander III back on, it ran just fine with it.

Thanks in advance for any information.

[x1rider]

I took a long hard look at ECM Spy yesterday and it seems like I may have a few options.

1. Just disconnect the sensor and ignore the check engine light.

2. Disconnect the sensor and check off the boxes related to the O2 sensor in the diagnostics section of ECM Spy, therefore the CEL will stay off.


3. Turn the O2 sensor off by checking out this box in the diagnostics section (and leaving the sensor plugged).


4. I'm pretty sure I read somewhere that the O2 sensor monitored the AFR at WOT and added some fuel if it became lean at WOT, therefore it may be a good idea to keep it in the loop. I could raise the O2 sensor active RPM to about 3700 in the ECM config section, so the O2 sensor would become active outside of my trouble area (2500-3500RPM).


5. This one would require some trial and error. I could raise the voltage where the sensor detects a rich mixture, therefore the sensor would be less "sensitive" and would stop trying to dangerously lower my AFV across the whole map and it would still be active in case of a lean condition. I guess I would have to try different voltages until it stops spitting through the intake and the AFV remains at 100%.


Have any of you guys played around with those values? Any suggestions?

Thanks

[glens]

Sparkplug electrode insulators don't show much color with "modern" fuels, and in any event it's always been the very bottom of the porcelain, deep down inside, where you look for the proper color anyway.

Why not just change all three sensor voltages in that last screenshot upwards by 0.25 volts?  I'd bet that would take care of your problem quite nicely.

Oh, and there's no way the O2 sensor is being polled at WOT.  That AFR should be well out of the sensor range (which has a lower [rich] limit of about 14.2:1 (gasoline) AFR.

The way I understand it, the Buell system uses just one AFV (per cylinder?) for the whole operational range, so it'd be pretty imperative that your fueling be correct otherwise in all areas, since any "O2" anomalies within the range of AFV development are what will get applied everywhere, even if it's not the right amount or even the wrong direction in other areas.

[x1rider]

Thanks for your input Glens.
You're right about the AFV, only the rear cylinder is monitored and whatever is "seen" in the closed loop part is applied to the whole map.  I don't understand why but I guess my closed loop area is too rich and the ECM automatically leans the whole thing.  I kid you not, the spitting through the intake is horrible, I can feel the difference in temperature inside my right leg, one time I thought I wouldn't even make it back home.
My only concern by raising the 3 voltage values is that I'm afraid since the middle will effectively be a richer mixture, the ECM may freak out and shoot the AFV down even more (may be OK though since the rich voltage value will be raised as well, I guess it's trial and error on that one).

[glens]

I'm pretty sure you'll find that if you raise all three voltages your AFV will stay higher, because what this'll do is cause the system to aim for a higher voltage from the sensor, and this is brought about by adding some fuel (or it sounds like in your case, at least not remove any) to get the sensor output there.

How do you personally ensure your fuel tables are correct? (just wondering)  For this system to work the best it can in terms of the AFV and whatnot, it'd be pretty important to have the fuel tables as accurate as possible.  If you need elaboration on that I'll try, otherwise I don't want to bore you unnecessarily.

If you don't change anything in the fuel tables (assuming they're otherwise correct) but increase the target O2 sensor output, more fuel will be required than with the lower targets.  If you were to increase the target voltage(s) as well as increase the fuel tables the applicable amount, you'd again be right where you are now.  Which sounds rather like your fuel tables aren't quite appropriate.  You really shouldn't be seeing much "color" on the plugs.

[x1rider]

I've contacted other forum members that have the same setup as me (Forcewinder intake, Force exhaust, Race ECM) and theirs, for some reason, work well.  I tried a few Race ECM eeproms but they all give me the same results, the bike works normally only with the O2 sensor unplugged.  The small range that the O2 sensor is active is enough to disturb the rest of the map.  I've heard that the Force exhaust is kinda hard to tune, maybe the reversion at that particular RPM really messes up the sensor input?  I really don't know.

[x1rider]

Update:  Since the bike runs well with the O2 sensor disconnected, I just ended up using ECM Spy to disable the O2 sensor so I can leave it plugged in but it doesn't do anything.  Funny thing, it still triggers a CEL when it's plugged in but disabled.  I used ECM Spy again to check off the CEL for the O2 sensor, now the light should stay off.
When I have more time I'll play around with the O2 sensor voltage but for now I'm pretty fed up, I've been trying to get that bike working right for 2 weeks now, haha!