Codes.
I pulled codes of the Golf today. P0134: O2S Circuit No Activity B1S1 P0135: O2S Heater Circuit Malfunction B1S1 P0172: System too rich B1 Obviously, the P0172 would be caused by a bad pre-cat oxygen sensor. As for the other 2 codes, they're both pointing to the pre-cat sensor. But my real question is this. I ran around for almost 6 months with no exhaust. The car ran way rich, to the point I could hear it misfiring almost constantly. Not anything severe, but some decent sized pops at closed throttle and under decel. Since there aren't any codes for the post-cat sensor, I'm thinking that my cat is fine, as well as the post-cat sensor. Would I be correct in this assumption? In reality, I should pull the plugs since they're probably fouled by now. But I'm way too lazy to do that.