With Service Bay Test

IMPORTANT: Verify the EVAP vent valve functions before proceeding with this diagnostic. You should hear or feel a click when commanded ON with a scan tool. A circuit condition can cause the solenoid to be inoperative without setting a DTC P0448, or a DTC P0449. Refer to DTC P0498 or P0499 .

Verify the EVAP system using the EVAP Service Bay Test. DTC P0455 should not set.
If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.