I have a 2003 grand prix gtp with 116,000 miles runs great under normal conditions! when you put it under a load {i.e. heavy boost, passing or at highway speeds in high gear it's almost like it's hitting the park limiter. I changed coil packs and module with no change. no codes or lights. Once it gets past a certain rpm generally around 4-4200 rpms it seem to pick up again. any feedback would be greatly appreciated. thank you!
Nov 23, 2014 at 5:57 AM