Purge Valve Leak Test

If the EVAP purge valve does not seal properly, fuel vapors could enter the engine at an undesired time, and may cause driveability concerns. The PCM tests for this by commanding the EVAP purge and vent valves closed, sealing the system, and monitoring the FTP for an increase in vacuum. If the PCM detects a calibrated increase in vacuum within a set amount of time on 2 consecutive tests, DTC P1441 will set.