Purge Valve Leak Test
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.
If the EVAP purge valve does not seal properly, fuel vapors could enter the engine at an undesired time causing driveability concerns. The Powertrain Control Module (PCM) tests for this by commanding the EVAP purge valve OFF, closed, and vent valve OFF, open, sealing the system, and monitoring the FTP for an increase in vacuum. If the PCM detects that EVAP system vacuum increases above a calibrated value, DTC P1441 will set.