p0455
Easy Fix
Chevrolet · Trucks
Evaporative Emission (EVAP) System Large Leak Detected
Quick Answer
Error code P0455 on your Chevrolet Trucks means: Evaporative Emission (EVAP) System Large Leak Detected. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Loose, damaged, or missing gas cap
  2. Cracked or disconnected EVAP hose
  3. Failed EVAP purge valve or vent valve
  4. Cracked charcoal canister
  5. Leaking fuel tank or damaged fuel filler neck
How to Fix It
1
Inspect the gas cap for cracks, damaged seal, or improper seating; tighten or replace
2
Perform a smoke test on the EVAP system to pinpoint the large leak
3
Inspect all EVAP hoses from the fuel tank to the charcoal canister and purge valve
4
Check the charcoal canister for visible cracks or damage
5
Repair or replace the leaking component identified by the smoke test
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
Gas cap
EVAP hoses
Charcoal canister
EVAP purge or vent valve
Related Error Codes
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