Diagnostic Aids

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

To help locate intermittent leaks, use the Evaporative Emissions System Tester (EEST) (J 41413-200), or equivalent, to introduce smoke into the EVAP system. Move all EVAP components while observing smoke using the High Intensity White Light (J 41413-SPT), or equivalent.
A temporary blockage in the EVAP purge solenoid, purge pipe or EVAP canister could cause an intermittent condition. Check and repair any restriction in the EVAP system.
To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles using the high intensity White light.
Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
For intermittent conditions, refer to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 3.1L CENTURY, GRAND PRIX & MALIBU article.