p0455
Moderate
GMC · Trucks
EVAP System Leak Detected (Very Large)
Quick Answer
Error code P0455 on your GMC Trucks means: EVAP System Leak Detected (Very Large). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Perform EVAP smoke test to locate leak
2
Inspect all EVAP hoses for cracks or disconnection
3
Check fuel cap seal and replace if damaged
4
Examine fuel tank for damage
5
Repair or replace leaking components
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
EVAP hose kit
Fuel cap
Fuel tank repair kit
EVAP charcoal canister
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