i'm installing my headers and exhaust later this morning, and there's a chance that I might not be able to put the cat on(wrong size), if I put the second O2 sensor behind my resonator on my Speedstate exhaust, would the CEL still come on, or does it have to be a cat?

thankx guys

 

yes, the CEL will still come on. The second O2 is to check for a lower voltage and therefore verify that the cat conv. is working. If they both send the ECU the same voltage, then . . . CEL.

A temporary solution is to wrap the second O2 element in foil and secure it under the car. This is highly illegal (as is driving without a cat). However, it will avoid a CEL for the time being.

It sounds like you are stand-up (at least from the EPA's perspective ) and will have a cat on there soon enough, so this should be a temporary fix.

The loss in backpressure (which helps scavenge the crap out of the cylinder) from not having a cat will probably have you wanting it back on ASAP. Shane at MHP (back in the fxtreme days) had a supercherger and removed the cat, and put it back on becasue of the loss of low end torque.

Sorry for the long reply. Hope this helps,
ac

 

I've been running my 2001 Tib without any cats for a while now and my cel never came on and it runs great. One of the mechanics at hyundai told me the cel would not come and he was right.