p0455
Moderate
GMC · SUVs
Evaporative Emission System Leak Detected (Gross Leak)
Quick Answer
Error code P0455 on your GMC SUVs means: Evaporative Emission System Leak Detected (Gross Leak). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Check fuel cap seal and tightness
2
Inspect all EVAP hoses visually
3
Perform smoke test on system
4
Check charcoal canister connections
5
Replace hoses or cap as needed
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Fuel cap
EVAP hoses
Purge valve
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