Preliminary Check
WARNING: This page is about a different car, the 2002 GMC Savana and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Perform fuel pressure relief procedure only after approved diagnostic procedures have isolated a CNG system component replacement or CNG system components require removal for other vehicle repairs. This vehicle is designed to start and operate on CNG.