Originally Posted By: bennuss
Reviving from the dead.
I had a p0420 on a buick century which cleared but the not ready refuses to go away.
Anyways I had a problem with my fuel pressure regulator which was changed and then I started getting a random misfire code for a while . I went back to the mechanic saying the fpr must have been bad but he said impossible he would see fuel in the pipe and it is just a diaphragm and it cant be bad and then that code stopped and I got the p0420.
The car has 220,000 miles and if the cat is shot I dont want to fix it. Would non-foulers work and what size? Do I just need a post-cat one and should I anyways change the o2 b1s1 for fuel economy reasons?
How are smog tests performed where you live? Someone might inspect your car, see that a non-fouler was connected, and fail your test. What is worse, is some states put people in jail for doing such things.
