Purge Valve Leak Test
WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
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 (A stuck open or partially open purge valve) will set. To diagnose, go to SELF-DIAGNOSTICS - 3.4L ALERO, GRAND AM, IMPALA & MONTE CARLO article.