Ok, here is what is going on since my last post. My
check engine light came on again so I had autozone give me the reading once again to give you guys the exact reading.
The results: P0420 (Catalyst Efficiency Below Threshold, Bank 1).
The background: I had a new Catalytic converter put on a year ago, shortly after that, my light came on, I took it back and had them put another cat on and again the light came on eventually. The light comes on randomly about every 2-3 months when driving highway speeds usually. I usually reset it and keep on trucking. Autozone told me to replace the O2 sensor however, this thing has a half dozen of those and they are 50 bucks a piece. I dont really want to replace all of them if I dont have to, should I take this to GM and pay them the 80 bucks to give me a more thorough reading or has anyone else encountered such a problem and had a fix for it. I did replace the first O2 sensor behind the cat but that didnt work either. Any suggestions would be greatly appreciated. Thanks.
