The EVAP system detected a large/gross leak. On the 987 this is most often a fuel cap left loose or not sealing, or a disconnected/split EVAP hose. Larger than the P0442 threshold but still no real drivability impact.
SYMPTOMS
- Check-engine light
- Fuel smell possible
- No drivability effect
LIKELY CAUSES
- Fuel cap loose, missing, or not sealing
- Disconnected or split EVAP hose
- Stuck-open purge/vent valve
- Cracked charcoal canister
DIAGNOSIS STEPS
- Check the fuel cap and filler-neck seal first
- Smoke-test to find the large leak
- Inspect EVAP hoses and valves
- Clear and confirm the fix
RELATED PARTS
- Fuel filler cap
- EVAP hoses
- EVAP purge / vent valve