Test Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Suburban, and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedure.
- 5
If conditions were not corrected, check fuel system. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article. - 6
If conditions were not corrected, a worn cam, worn intake or exhaust valves, or other engine mechanical failures may be at fault.