P0455 on GMC Yukon: Symptoms, Causes & DIY Fix
Official technical diagnostic wire for fault code P0455 (P0455: Evaporative Emission Control System Leak Detected (Gross Leak)) specifically affecting GMC Yukon vehicles equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.
1. Symptoms of P0455 on GMC Yukon
When the Engine Control Module (ECM/PCM) on your GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax) logs fault code P0455, drivers commonly observe:
2. Most Likely Causes on GMC Yukon
Historical warranty claims and technical repair bulletins for GMC Yukon point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for GMC Yukon
Remove gas cap, inspect rubber O-ring for cracks, tighten until it clicks 3 times. on the GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.
If the cap rubber is dried or cracked, replace with genuine OEM cap ($15). on the GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.
Disconnect electrical plug and vacuum hose. Apply 12V; verify valve seals tight when unpowered. on the GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.
Check vent valve for road salt corrosion or spider nest clogs. on the GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.
Pump mineral oil smoke into EVAP port to reveal any hairline cracked lines. on the GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.
4. GMC Yukon P0455 FAQs
What causes code P0455 to trigger on a GMC Yukon?
On the GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax), P0455 is most frequently caused by Missing, loose, or cracked gas cap seal or Faulty EVAP purge control solenoid. Factory sensor degradation or wiring harness wear near the engine bay are common factors.
Can I safely drive my GMC Yukon with code P0455?
Yes. Completely safe to drive, but emissions test will fail. Given that P0455 carries a Low severity rating on GMC vehicles, we advise performing diagnostic scanning via the OBD-II port located driver side under steering column before extended highway driving.
Where is the diagnostic port located on the GMC Yukon?
The 16-pin OBD-II DLC connector on the GMC Yukon is situated driver side under steering column. It requires no special tools to plug in a standard scanner.
How much does it cost to fix P0455 on a GMC Yukon?
DIY replacement parts typically range between $15 - $250 (DIY: $15 - $50). If serviced at an authorized GMC dealership, expect an additional $120–$250 in professional labor based on their $125/hr hourly rate.