Section 10 (Engine Controls - Tests W/Codes - 3.1L Engine): Introduction
WARNING: This page is about a different car, the 1998 Pontiac Grand Prix, 1998 Chevrolet Monte Carlo, 1998 Chevrolet Lumina, and 1998 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
Most engine control problems are the result of mechanical breakdowns, poor electrical connections or damaged vacuum hoses. Before considering the computer system as a possible cause of problems, perform basic diagnostic procedures in the BASIC TESTING - 3.1L article. Failure to do so may result in lost diagnostic time.
If no faults were found while performing basic diagnostic procedures, proceed with DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If no fault codes are present and driveability problems exist, proceed to TESTS W/O CODES - 3.1L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.). If only intermittent codes are present, see INTERMITTENTS in TESTS W/O CODES - 3.1L article.