Every 12 500 km (7,500 Miles)
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect the CNG fuel lines and the fittings for leaks.
- Inspect the CNG fill valve O-ring.
- Inspect the CNG fill valve filter.