Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
2002 Pontiac Sunfire Problem Reports
RepairPal Verified 2002 Pontiac Sunfire Problem Reports
The serpentine belt tensioner can fail; it may become noisy and/or the belt may jump off. Replacement of the failed tensioner will be necessary.
An automatic transmission fluid leak may develop from the rubber section of a transmission cooler line. In some cases the rubber section of hose can be replaced. In others, the complete cooler line must be replaced to correct this type of leak.
A door window may move slowly or stop in mid travel due to a failing power window motor. The affected window may start working again after the motor cools off. Replacing the faulty window motor will commonly correct this concern.
The turn signal switch in the steering column may fail causing the turn signals not to work on one or both sides.