Hi davisg,
I didn't know if you still had your Grand Prix or not, but had another member on this site reply that he finally found a fix to that Chugging that we both were having with our Grand Prix.
From surferstick:
I had the stock PCM reflashed to the updated code mentioned in the TSB. It's now been months, and not a single problem since, so this fixed it for sure. Even better, the car now feels as strong as my old 99 did. I always felt I lost some power when I traded my 99 GT for this 05 GT, and now I've got my missing power back too.
Happy New Year folks.
I haven't gotten mine flashed yet, but will check into it.
Just wanted to pass this along to ya.
Later....... Steve!
