when the engine light comes on is a steady light or does it flash also when its on does you car feel different when its idlying, does it ever stall?. if its a steady light and when the light is on the car has a rough idle as in more shaky then ussual or anything like that it could mean you have a misfiring cylinder either by no preasure in the valve or just a bad spark plug. If its not what i described post on how the car feels when the light is on if there is any differences give me a bit more and maybe i can help ya out
anywho if i was u id just scrap the sunfire after having one and fixing more problems then i can post including 3 engines i can tell you its a crap car.
anywho hit me up with more info and maybe i can help ya out