Pontiac Repair: check engine light, spark plug wires, grand prix gtp

Question
I have a 02 Grand Prix GTP. When my fuel level gets below a quarter, and I accelerate hard to pass someone (around 140 KM/hr)the check engine light flashes about 10 seconds then goes out.It doesn't run any different when it happens.If theres over a quarter tank, the light will never come on. I'm taking the car in soon but would like some idea of whats happening. I've only had the car a couple months and have done no repairs. About a week ago the light stayed on (solid-no flashing)after flashing but I unhooked the battery and the lights out now. Drives me nuts, any time I'm under a quarter tank and step on it on the highway, the light will flash, but runs fine.

Answer
Hey Jamie:

well the light on flashing is not a good thing. It indicates a misfire that is bad enough to cause catalitic converter damage. Why it would only happen on a 1/4 tank of gas or less ??? It may be a fuel pick up issue where your loosing fuel pressure. That engine has a 2 speed fuel pump under a heavy load the pump runs faster and the pressure is boosted up to go along with the boost the super charger ads to the engine. Possably a plugged or restructed fuel filter could be the issue here. It might not be a bad idea to do a basic tune up on this engine especially if it has a lot of miles on it say more the 75,000 or so. the plugs "are good" for 100,000 but changing them sooner is not a bad idea and only use AC Delco plugs. another thing is the spark plug wires same thing only Use AC delco wires or a VERY good name brand set like Bosch or a set of premium wires from NAPA or Carquest. Good luck :)