The leak test found a small leak in the fuel vapour system. The driver usually sees only the engine light.
Likely causes, most common first
- Worn fuel cap seal
- Cracked EVAP hose
- Leaking purge or vent valve
- Leak at the fuel filler neck
Parts usually involved
- Fuel cap
- EVAP hoses
- Purge valve
- Vent valve
Test before you replace
Inspect the fuel cap seal, then smoke test the system to locate the leak.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.