i have a 2001 Grand Prix se and the service engine light came on about 4 months ago. i took it to advanced and got them to run the test and they told me it was something with the fuel system and then told me it was probably the EGR valve. so i buy a new one and replace it. after replacing it i unhooked the battery for about 5 min to see if it would reset and it didnt. so then the next day i took it back and got them to erase the code. well the code was gone until i turned the car off and back on. so now i have no idea what it could be. i have a family member thats a mechanic that told me that it prob isnt anything important and that the computers on these cars are so specific about things that it could just be my gas cap; but my ocd kicks in and that stupid light annoys me so much. any suggestions will help.