Possible Causes & Corrections

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Check the following items:

Poor fuel quality or proper octane rating.
Low coolant.
Loose drive belt.
Restricted air flow through radiator or condenser.
Proper cooling fan(s) operation.
Front air dam missing or damaged.
Knock sensor circuit system for no spark retard during knock condition.
Torque converter clutch operation.
Engine running lean. Monitor long term fuel trim on scan tool.