Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP system test runs when engine is first started and meets the Conditions For Running the DTC. See CONDITIONS FOR RUNNING DTC . An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at EVAP vent valve inlet or a pinched vent hose. A blockage in vent system will also cause a poor fuel fill problem. Repair blockage in EVAP system.
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 refer to INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.