Carry Out On-Board Diagnostics
WARNING: This page is about a different car, the 2003 Mercury Sable and 2003 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
After a road test, with the vehicle warm and before disconnecting any connectors, carry out the Quick Test using the scan tool. Refer to the SELF-DIAGNOSTICS - CNG, FLEX-FUEL & GASOLINE article for diagnosis and testing of the powertrain control system.