Fuel System Pressure Release: Notes
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.
WARNING:
Venting of natural gas to the atmosphere may be prohibited in some areas. Before venting the Compressed Natural Gas (CNG) fuel tank, contact the local gas company to ensure that all local, state and federal regulations are observed.