Investigating P0455 on Your 2020 Chevrolet Traverse
A P0455 on your 2020 Traverse means the ECM detected a large EVAP leak. Your 2nd-generation Traverse with the 3.6L V6 is out of GM's basic warranty but covered by the federal emissions warranty. The gas cap is the prime suspect.
Evidence
- Check engine light with P0455
- Faint fuel odor near the rear
- Gas cap seal worn after 5+ years
- Failed emissions test
Causes Ranked
- Gas Cap Seal (Very High Likelihood): Worn rubber seal. Replace for $10–$25.
- Vent Valve Solenoid (Medium Likelihood): GM's vent solenoid sticking. $100–$200.
- Purge Solenoid (Medium Likelihood): Stuck open. $80–$180.
- Vapor Line (Low Likelihood): Cracked hose. $80–$200.
- Charcoal Canister (Low Likelihood): Saturated. $200–$350.
Diagnostic Path
Replace the gas cap ($10–$25), clear the code, drive 2–3 cycles. If P0455 returns, a smoke test will locate the leak. The vent valve solenoid is near the charcoal canister under the rear.
Warranty Coverage
GM's basic warranty (3yr/36k) has expired. The federal emissions warranty (8yr/80k) covers EVAP through 2028. Contact your dealer.
Safe to Drive?
Yes. P0455 doesn't affect the Traverse's 3.6L V6, 9-speed automatic, or AWD.