P0455 Code: 2023 GMC Yukon – What It Means & Cost to Fix

2023 GMC Yukon P0455: Large EVAP Leak Diagnosis

P0455 on Your 2023 GMC Yukon

A P0455 on your 2023 Yukon means a large EVAP leak. Whether you have the 5.3L V8, 6.2L V8, or 3.0L Duramax diesel, gas-powered variants share the same EVAP system. Check for P0449 companion code. Gas cap first.

Symptoms

  • Check engine light with P0455
  • P0449 may also appear
  • Possible fuel smell
  • Gas cap not seating

Top Causes

  1. Gas Cap Seal (Very High Likelihood): Loose or defective. Warranty-covered.
  2. Vent Valve Solenoid (Medium Likelihood): GM's known EVAP weak point. Warranty-covered.
  3. Purge Solenoid (Medium Likelihood): Stuck open. Warranty-covered.
  4. Vapor Line (Low Likelihood): Connection issue. Warranty-covered.
  5. ECM Software (Low Likelihood): Calibration update. Warranty-covered.

Warranty

Your 2023 Yukon is under GM's 3-year/36,000-mile warranty through 2026. Federal emissions (8yr/80k) covers EVAP through 2031.

Safe to Drive?

Yes. P0455 doesn't affect V8 performance, 4WD, Magnetic Ride, towing, or any features.

Frequently Asked Questions

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