I have an 02 Grand Prix GT. I lose a lot of power when i put a heavy load on the accelerator or when i am on an incline. From the discussions i have read, this problem is common. I also learned that it is hard for anyone on here to help if their are no codes. That being said, if i go to advance auto parts and have them run a test, will any codes come up if my SES light is not on? Also, if anyone has any has any suggestions as to what the problem is with my car that would help to.