Section 20 (Engine Controls - Basic Diagnostic Procedures - 3.1L): Summary
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.
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, no trouble codes (or only intermittent ones) were found while performing ON-BOARD DIAGNOSTIC SYSTEM CHECK and driveability problems exist, proceed to appropriate TESTS W/O CODES - 3.1L article for diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.) or intermittent diagnostic procedures.