GM-GMC: service engine soon light, pontiac grand prix, comunicating

Question
I have a 1994 pontiac grand prix. the service engine light only comes on when your doing over 50 miles per hour and leave off the throttle. Please help. thank you

Answer
Jason,  

  Your best bet is to take your pontiac to a reputable shop and have them "scan" the computer for code. Since the check engine light comes on and it does it consistantly this should be an easy fix for any shop capable of comunicating with the vehicles ECM. Without knowing what code the Computer is setting I would just be guessing! Hope this helps.