my check engine light came on a few days ago. i know that nothing is seriously wrong with my teg. but i wanna find out what the prob is and get it fixed. is it true that if i bring my car to auto zone they have a little computer they can hook up and tell me what the prob is. i thought it was the fuel filter but i just replaced it and took the negative terminal off my battery. after a few seconds the light came back on though. thanks in advance for any input you guys might be able to give me.