1999 Pontiac Grand Prix Failed Emission Test

MASE2524

MEMBER
1999 PONTIAC GRAND PRIX

Engine Mechanical problem
1999 Pontiac Grand Prix 6 cyl Wheel Drive Type unknown Automatic 130000 miles

Hello,

I have been taking my car back and forth to the mechanic getting my car inspected for two months now. Each time my car fails the emission test: catalyst, EGR valve and the E Vap. The mechanic keeps telling me that it's because I recently changed my battery and that I just have to continue to put miles on it and eventually the computer will readjust. I've been having it checked every week and it still has not passed emissions. The mechanic is telling me there is really nothing I can do and I just have to keep driving it and the problem will fix itself. Is there another solution? I do not want to get a ticket for not having my car inspected, eventhough I have been trying every week. Is it possible to get one if not all problems fixed? How much would it cost ball park figure? Please advise. Thank you!

1 Reply

SERVICE WRITER

MECHANIC
9,123 POSTS

So I understand: The Check engine light is NOT on. The monitors have not all run, correct?

There is a specific drive cycle that can be done to set the monitors.

Each emission monitor goes through a specific self -test procedure and has different criteria, nothing to do with the PCM adjusting anything.

Mitchell one should have the drive cycle in it. A competent shop may need to troubleshoot this.

One thing that can hold up the monitors from running is a need a good MAP/BARO signal. Both signals must be there. A bad map sensor can cause this.