Evaporative Emissions System: Testing and Inspection

DIAGNOSIS
Poor idle, stalling and poor driveability can be caused by the following conditions:
^ Malfunctioning EVAP purge solenoid.
^ Damaged canister.
^ Hoses split, cracked and/or not connected properly.

An incorrect EVAP purge system flow should set a DTC P0441. A continuous purge condition with no purge commanded by the PCM should set a DTC P1441. An electrical fault in the EVAP Vacuum Switch circuit should set a DTC P1442.

EVAP Purge/pressure Station:

The EVAP system purge/pressure diagnostic station is used to clear carbon released into the EVAP system by the canister. Carbon released into the EVAP system may cause EVAP system components to be inoperative. If diagnosis indicates that an EVAP system component needs to be replaced, the system should be checked for released carbon. A released carbon condition must be corrected before replacing any EVAP system component. Procedures for checking the EVAP system for released carbon and for correcting a released carbon condition are in the Diagnostic Aids for the applicable DTC tables.

LEGEND
(1) Main Valve
(2) Evaporative Emission System Purge/Pressure Diagnostic Station J 41413 or equivalent
(3) Nitrogen Cylinder
(4) Black Connecting Hose
(5) Threaded Fitting
(6) Gauge Set