My Kid ran over something on my 2002 Impala LS 3800 and took out the whole exhaust. Replaced everything then started getting the check engine light. Muffler guy replace the Cat Conv and said that that was the last one I get even though I still had a code for it. Threw O2 sensors MAS and some swear words at it. Seems like the light would burn out soon. Don't notice too bad of performance drop.

My new mechanic says that there is a solid pipe coming from the manifold that should be flex. Says that is what is throwing codes. THOUGHTS??? PLEASE???

 

what was the code and definition? i dont believe it should be flex because most of the time flex pipe isnt made out of high heat material like normal pipe is. there should be a manifold for the front and back of the motor coming into a y pipe then to the cat then to the muffler then out from there.

 

The latest code was bad O2 sensor. I need to go get it read again after my new rebuilt transmission, cv shafts on both sides, and brake job. Will let you know. thanks for the help.

 

Your mechanic is stupid. There is no flex in a stock exhaust pipe. Get the codes read.