EVAP Service Port
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP service port is located in the EVAP purge pipe between the EVAP purge solenoid and the EVAP canister. The service port is identified by a Green colored cap.