Section 24 (Engine Controls - Tests W/Codes): Summary
WARNING: This page is about a different car, the 1998 Buick Riviera. However, it is still accessible from the selected car via links, so may be relevant.
If no hard fault codes are present, driveability symptoms exist or intermittent DTC(s) exist, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.