My daughter has an 2002 Optima that had the same problem. Ran several hours of troubleshooting including removing and checking the canister, which was fine. I finally found a one way check valve that was installed backwards (at the factory). As soon as I disconnected the valve, the pressure instantly released. We reversed it and the car took fuel normally. The valve has the flow arrow molded on it. It should point toward the fill cap, not to the tank.
Sunday, August 21st, 2011 AT 8:41 PM