I put this in Power FC forum but only got one reply so I thought I'd try here....

Single turbo using a power fc with all the required mods and removed all emissions stuff including air pump (for track purposes of course!) can I disable the O2 sensor in power fc? Should I? I suspect mine needs to be replaced but do I even need this?

Rotorhead333 replied:

I have shut mine off, I have noticed that w/ the O2 turned on that it tries to lean the mixture too much from what you have it set at in the PFC. I'd say, if you are racing it, leave it off. If you are cruisin around town, go ahead and turn it on for added clean up of emissions. If you think you need a new one and it's not working correctly, keep it off.

I always thought mine ran better w/ it off, probably cuz it's running rich like it should. Hope this helps.

(Thanks again for this reply rotorhead333!)

I was told O2 sensor will only make difference at idle and cruise or is it simply for emissions? Anyone else have any feedback? Is this responsible for fine tuning that is done on the fly by the ECU for differences in ambient air temps and pressures or can a good tune/map manage the engine without this input?

Shawn

 

I also have mine turned off. Seemed to idle much better without it. I now only run av-gas so my 02 sensor it going to die quickly anyway.