P0455 on Ford: Evaporative Emission System Large Leak Detected
Severity: 1 of 4
Safe to drive in most cases. Check the gas cap right away. If you smell strong raw fuel or see dripping fuel, park it and get it inspected, because that may be a liquid leak rather than a vapor leak.
Estimate range covers the repairs listed below; see the cost breakdown. A flashing check engine light, a hot temperature gauge, or brakes that feel different mean stop driving and get help.
What P0455 usually means on a Ford
Ford EVAP purge valves are a well known cause of P0455, and a stuck open purge valve can also cause hard starting right after refueling.
Most likely causes on Ford vehicles
- Gas cap
- Purge valve
- EVAP hoses
Order reflects cost and likelihood in general; your vehicle may differ. Confirm with testing before buying parts.
Ford specific tips
- Hard start after refueling strongly suggests the purge valve.
Estimated repair cost
This is an estimate, built from typical parts price ranges plus labor hours times an assumed shop rate of $110 to $190 per hour. Actual prices vary by vehicle, region, and shop. Diagnosis fees are often extra.
| Repair | Parts | Labor | Estimate (low / high) |
|---|---|---|---|
| Gas cap | $10 to $35 | 0.0 to 0.1 h | $10 + 0.0 × $110 = $10 $35 + 0.1 × $190 = $54 |
| EVAP hose | $15 to $80 | 0.3 to 1.0 h | $15 + 0.3 × $110 = $48 $80 + 1.0 × $190 = $270 |
| Vent or purge valve | $25 to $150 | 0.3 to 1.5 h | $25 + 0.3 × $110 = $58 $150 + 1.5 × $190 = $435 |
Costs are generic for this code; parts and labor on some Ford models may run higher.
Watch a repair video
How To Fix Large Evap Leaks On Your Car P0455 (Scotty Kilmer). Third-party video, loads from YouTube (privacy-enhanced mode) only when you press play. Procedures vary by vehicle. Search YouTube for “P0455 Ford fix” videos.
Repair manuals
Step-by-step service manuals for Ford with torque specs and wiring diagrams:
Haynes manuals for Ford Chilton manuals
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Check Ford recalls
Enter your VIN at the NHTSA recall lookup before paying for repairs.
FAQ
Is the purge valve cheap?
Fairly, and it is usually easy to access under the hood.
Read the full P0455 guide or more Ford check engine notes.