P0455: Evaporative Emission Control System Leak (Large)
P0455 signals a large leak in the EVAP system. Cheapest fix is almost always the gas cap.
Severity: low · System: Powertrain · Safe to drive: usually, short-term. Not dangerous. Check the gas cap first, then have a shop smoke-test the system.
Symptoms
- Check engine light
- Fuel smell around vehicle
Common causes
- Missing or badly damaged gas cap
- Disconnected EVAP hose
- Failed vent valve
Fair repair prices
| Gas cap replacement | $20–$60 |
|---|---|
| EVAP vent valve | $100–$250 |
| EVAP hose reconnect/replace | $80–$300 |
Ranges are US market averages (parts and labor). If your shop's quote is above the high end, ask for a line-item breakdown or run it through the invoice checker.
Other codes
- P0300 — Random / Multiple Cylinder Misfire Detected
- P0301 — Cylinder 1 Misfire Detected
- P0420 — Catalyst System Efficiency Below Threshold (Bank 1)
- P0430 — Catalyst System Efficiency Below Threshold (Bank 2)
- P0171 — System Too Lean (Bank 1)
- P0174 — System Too Lean (Bank 2)
- P0442 — Evaporative Emission Control System Leak (Small)
- P0128 — Coolant Temperature Below Thermostat Regulating Temperature