Quick O2 sensor question - rears only for emissions testing?
12-26-2008, 01:20 PM
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Quick O2 sensor question - rears only for emissions testing? I've been reading the guides and figuring out what all to do for my car, while staying street legal. ish.
So we do OBDII testing in Colorado - I'm reading about the different types of headers, and just want to ask a quick clarification question - the rear O2 sensors, are they used for A/F ratio or closed loop ops at all, or only for emissions verifying that the cats are working?
I don't want to program out something that is actually doing something for maintaining engine tune, but if it's just checking for the emissions systems, I don't care so much, if you know what I mean.
So we do OBDII testing in Colorado - I'm reading about the different types of headers, and just want to ask a quick clarification question - the rear O2 sensors, are they used for A/F ratio or closed loop ops at all, or only for emissions verifying that the cats are working?
I don't want to program out something that is actually doing something for maintaining engine tune, but if it's just checking for the emissions systems, I don't care so much, if you know what I mean.
12-26-2008, 01:39 PM
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Rears are there to test the catalitic converter to make sure is say not cloged. It works with the fronts and I think it compare the values in the PCM and if they are way off it will set off a SES light of catalitic converler low threshold.
