I have a quick question about the rear o2 sensors. I know their main purpose is to tell the PCM if the converters are working right, but is that it? If they tell it that they are not working, will the car run any different or will it just throw a code and the SES light? The reason I ask is because I am in the middle of installing some long tubes and I don't want to shell out $50 for sims when I'll just have tuned out in a few months (after I get a cam). I will be driving it b/t now and then, so does anybody see a problem with not using any rear sensors/sims at all?

 

you're ses light will go on...but other than that should be just fine.

I have a set of sims for sale if you want...$30 shipped.

 

Yea, the SES light will stay on, but other than that, absolutely nothing will be affected, except the ozone.

I'll take the sims if he doesn't, if you take paypal. PM me if he doesn't want them. Mine are already programmed out, but I would like to plug the rear O2 connectors with something, instead of having them open.

 

Great. I don't want the sims. I'll be getting a tune in a few months, I'll live with the light until then. Thanks.

 

The rear O2's will change injector pulse width to find 14.7 afr non-wot, so if you are running no cat your injector pusle width will be shorthen and your long term will change also. If you are just running long tubes, I think you will be ok.

 

Really? This sounds different than the other two. Does anybody else agree with this guy?

 

You're talking about the front O2 sensors. The rear O2's don't adjust a/f ratio.

Dan

 

Rear o2 also do the same as far as changing injector pulse width. I will double check tomorrow with my gm master tech.