Parts
$0–80
P0455 — EVAP Large Leak Detected
SAFEIs it safe to drive? A big fuel-vapor leak. Not a drivability hazard; will fail emissions and you may smell fuel.
What P0455 means
A large EVAP leak — most often a gas cap that's loose, missing, or not sealing.
Most likely causes (in order)
- Gas cap off / loose / failed seal
- Disconnected or split EVAP hose
- Stuck-open purge or vent valve
- Damaged filler neck
Symptoms you might notice
- Check-engine light
- Fuel smell, especially after fill-ups
What to check first
Confirm the cap seals; inspect EVAP lines for a disconnect or split. Smoke-test to pin a large leak quickly.
Repair cost & difficulty
Labor
0.1–1 hr
Difficulty
Easy DIY