Took my black GTA to the Pontiac Southern Nationals last month. The car ran perfect from Arkansas to Dallas, and then on the afternoon of day two Hector proceeded to run increasingly badly on the trip from Ennis back to DFW. Finally by the time I got it back to a friend's house in Arlington, it would not start and idle any length of time that night. The old "tap the MAF with a screwdriver" test told me the MAF was likely bad, so I got one from Auto Zone and it seemed to clear up.

On the drive back home the next day, the car alternated running just fine and then at times the tach looked like an EKG machine wildly swinging up and down and the car was stuttering badly. But I was able to drive out of it eventually. Never any SES light at all the whole trip and now the car flips a coin every time you start it up I guess: one time fine, one time jumpy yet it never tries to really die. So I think I still have something else going on; anyone else ever experience symptoms like this with their car(s)?

 

check your 2 relays and their ground circuits