2001 gran prix shakes when accelerating. Engine light blinks on and off
A flashing check engine light usually means it's a misfire. Check your spark plugs and wires. Also, get your codes read if you can. Most autoparts stores can do this for free.
Mine did the same thing....needed a tune-up (plugs and wires fixed the problem). Depending on where you live and if you can do it yourself, parts are about $100 (depending on what type of plugs you buy)
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts