1998 3.8 Grand Prix 185K on it. Tuneup last yr. including fuel filter. Not showing any codes. I cleaned the EGR valve and the plunger works.(it was carboned up).With the engine cold it runs like new, soon as the temp gauge goes up it will stutter if I press hard on the accelerator. Mileage seems to be normal. Throttle body is clean. One of the coil packs had corrosion on the towers so I changed that. It runs fine if I don't get on it. Alittle rough idling. Any ideas friends?
Will