Error code P0455?

2003 GMC YUKON
300,000 MILES • 5.3L • 4WD • AUTOMATIC
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YUKONXLT
  • MEMBER
  • 4 POSTS
error code P0455
Sep 13, 2026 at 1:28 PM
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MECHTRIX
  • ✓Experienced Mechanic
  • 529 POSTS
Po 455 means there was a leak detected bu the ecm it performed a test and found a (large leak / no flow ) somtimes it just needs a new gas cap and other times there a cracked line . Diss connected line stuck purge valve all you van do right now is check everything and if you see somthing cracked broken leaking disconnected in the evap system replace it ..good luck
Sep 14, 2026 at 6:54 AM
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