Thread: 2003 Grand Prix

Hello all,
I joined the Grand Prix forum so I could find answers to issues with my daughter's 2003 Grand Prix, since I am so lucky as to be the one she turns to for help when something goes wrong. I am thankful for any help you all can provide as well as willing to help whenever I am able to do so.
Thanks to all,
Bob Funk

Hey Brandon and all,
I believe it is a GTP Model, Silver in color. She has been having some problems where the engine will race up and down as she drives. Sometimes it acts as though the cruise control is on. At first she thought it was a transmission problem. We were going to take it to a transmission repairman, but after I drove it, I thought it acted the same as my wifes Cadillac when the Idle Air Control Valve went bad. I replaced that and performed a good cleaning of the Throttle Body. It helped, but it has now been several weeks since this was done and she claims it is still acting up. She also said it acts worse in the afternoon after the outside air has heated up, and really acts up (lurching and jerking and high reving at stop lights, etc.) when she runs the AC. I have not driven it since she brought it to me yesterday to look at it. So tomorrow I will drive it again and try to see how it is acting and figure out what it might be. My next thought is the Mass Airflow Sensor may be bad, but I am not getting a check engine light or a code, so I really don't know. Any help would be appreciated.
Thanks,
Bob