Investigating P0455 on Your 2020 Toyota Tundra
A P0455 on your 2020 Toyota Tundra means the ECM found a large EVAP system leak. Your 2nd-generation Tundra with the 5.7L i-FORCE V8 is out of basic warranty but covered by the federal emissions warranty. The gas cap is the most common cause—and on full-size trucks, EVAP components near the fuel tank see more road exposure.
Signs Present
- Check engine light with P0455
- Faint fuel smell near the tank area
- Gas cap seal worn after 4–5 years
- Failed emissions test
Causes by Probability
- Gas Cap Seal (Very High Likelihood): Worn rubber seal. $10–$20 OEM Toyota cap.
- Canister Close Valve (CCV) (Medium Likelihood): Vent valve sticking. $150–$260.
- EVAP Hose Damage (Medium Likelihood): Road debris exposure on the full-size frame. $80–$240.
- Charcoal Canister (Low Likelihood): Physical damage or saturation. $200–$450.
- Purge VSV (Low Likelihood): Vacuum switching valve. $100–$220.
Diagnostic Steps
Replace the gas cap ($10–$20). Clear the code and drive 2–3 cycles. Inspect EVAP components under the truck for physical damage. If P0455 returns, a smoke test will find the leak.
Warranty Coverage
Toyota'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 Tundra's 5.7L V8, 6-speed automatic, 4WD, or towing capacity.