Section 293 (Engine Controls - Trouble Shooting - No Codes): INTERMITTENTS: Preliminary
WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
See SYMPTOMS for the Important Preliminary Checks Before Starting. The fault must be present to locate a problem using the DTC table. If a fault is intermittent, use the DTC tables may result in the replacement of good parts.