2001 grandprix gt
It had a po420 code about 2 yrs ago, I put in a oxygen sensor pipe entender and the code went out. I also had the resonator removed eventually when it went bad.
I sold the car to a family member oct 2015... In may of 2016 the straight pipe where the resonator/straight pipe was welded to the downpipe cracked. SO I told him to go get a straight pipe re welded where it was originally attached
Fast forward to today I'm working on the car trying to figure out the po446 , I changed the vent valve but code still remains. I also noticed that the exhaust is stronger than I remember. I get under the car and the converter is gon as well, its straight piped all the way to the mufflers. crazy things is its not throwing a p0420 code at all.
I guess i should have went with him to the exhaust shop, not sure if it'll be a problem but Im sure thats not what he really wanted done.
Didn't think that would be possible to not throw the 420 code. Just wanted to share that story
