EVAP system small leak detected

What the code means

The sealed fuel-vapor system did not hold the expected pressure or vacuum during its monitor.

Severity and driving

Usually safe to schedule unless fuel odor or liquid leakage is present

Plausible causes

Loose/damaged fuel cap or seal
EVAP hose leak
Purge or vent valve leakage
Filler-neck sealing issue

Next checks

Stop and seek help if raw fuel is visible or strongly smelled
Check that the cap is correctly tightened if applicable
Use smoke testing for precise leak location

Source and boundary

Code structure follows SAE J2012. Manufacturer-specific definitions, pinpoint tests, wiring, torque, fluids, and repair procedures require authoritative information for the exact vehicle.

SAE J2012 Diagnostic Trouble Code DefinitionsReviewed 2026-08-13

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