Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect for the following conditions, which may cause a diesel oxidation converter (DOC) to degrade:
- Off Road Fuel or Red Dye Fuel
- Low quality B-20 fuel
- Fuel Containing high sulfur content
- Engine oil or coolant consumption
- Leaking fuel injectors
- Inspect the DOC for the following conditions:
- Physical damage or alterations
- Internal rattles caused by a damaged catalyst substrate
- Exhaust leaks before or after the DOC.
- If a condition is found, replace the DOC.
- If all exhaust system inspections are normal, replace the DOC.
IMPORTANT:
Perform the Repair Verification after completing the Circuit/System Testing.