Tracking P0455 on Your 2021 GMC Yukon
A P0455 on your 2021 Yukon means a large EVAP leak. Whether you have the 5.3L V8, 6.2L V8, or 3.0L Duramax diesel, the gas-powered variants share the same EVAP approach. Check for P0449 companion code. Gas cap first.
Evidence
- Check engine light on
- P0455 and possibly P0449
- Possible fuel smell
- Gas cap issue
Causes Ranked
- Gas Cap Seal (Very High Likelihood): Loose or worn. $10–$25.
- Vent Valve Solenoid (Medium Likelihood): GM's known EVAP weak point. $100–$230 installed.
- Purge Solenoid (Medium Likelihood): Sticking valve. $110–$250 installed.
- Vapor Line (Low Likelihood): Connection issue. $80–$230.
- Charcoal Canister (Low Likelihood): Saturated. $190–$400 installed.
Warranty
Your 2021 Yukon's basic warranty (3yr/36k) has likely expired. Federal emissions (8yr/80k) covers EVAP through 2029. The Yukon may still be under GM's 5-year/60,000-mile powertrain warranty through 2026.
Safe to Drive?
Yes. P0455 doesn't affect V8 performance, 4WD, Magnetic Ride, towing, or any features.