Solving P0455 on Your 2020 Ford F-150
A P0455 on your 2020 Ford F-150 means the PCM found a large EVAP system leak. Your 13th-generation F-150 (final year of this generation) is out of Ford's basic warranty but covered by the federal emissions warranty. EVAP components on the F-150 sit near the fuel tank under the bed.
Signs Present
- Check engine light with P0455
- Fuel smell near the bed or tank area
- Gas cap seal worn after 4–5 years
- Failed emissions test
Causes Ranked
- Gas Cap Seal (Very High Likelihood): Worn rubber seal. $10–$25 for OEM Ford replacement.
- Canister Vent Solenoid (Medium Likelihood): Ford vent valve sticking, exposed to road debris. $140–$260.
- EVAP Hose Damage (Medium Likelihood): Road debris or corrosion. $80–$240.
- Vapor Management Valve (VMV) (Low Likelihood): Ford purge valve. $100–$220.
- Charcoal Canister (Low Likelihood): Physical damage. $200–$400.
Diagnostic Path
Replace the gas cap ($10–$25). Clear the code and drive 2–3 cycles. FORScan reads Ford-specific data. For professional diagnosis, smoke testing pinpoints the leak.
Warranty Coverage
Ford's basic warranty has expired. The federal emissions warranty (8yr/80k) covers EVAP through 2028. Contact your dealer.
Safe to Drive?
Yes. P0455 doesn't affect the F-150's engine, 10-speed automatic, 4WD, or towing.