Possible Causes & Corrections
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Check for the following:
- Inspect the Evaporative Emission (EVAP) system and fuel tank venting.
- Inspect fuel injectors for leakage or diagnose fuel system. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 4.3L SIERRA & SILVERADO article.