I recently changed my O2 sensors due to the CEL light on my dashboard. I have a test pipe and had the bung(metal filter) installed before, and the CEL was gone for a while. After installing new O2 sensors, its popping up again. What could be the problem? Let me know guys!!!!

 

What code is it? P0420 right. Your rear O2 is still seeing to much crap. Do the antifouler method and you'll be good to go

 

+1 or just delete it from your ROM and be done with it.

 

I've gotten a P0420 even with a stock cat, so I think some sensors are more sensitive than others.

 

Buy a CEL fix you should be fine

 

as he said for like 10 bux problem solved