P0455 — EVAP System Leak Detected (Large Leak)
Low severityWhat it means
The evaporative emissions system has a large leak — often as simple as a fuel cap that was left off or not clicked shut after refuelling. Larger leaks can also come from disconnected hoses or a failed vent valve.
Common symptoms
- Check engine light, often right after refuelling
- Noticeable fuel smell in some cases
Likely causes
- Fuel cap missing, loose or not sealed (most common)
- Disconnected or split EVAP hose
- Failed vent or purge valve stuck open
- Cracked charcoal canister or filler neck
What to check first
- Check the fuel cap first — refit it until it clicks, clear the code and drive
- Look for disconnected hoses around the tank and canister
- Test the vent valve operation
- Smoke test the system if the code returns
Can you keep driving?
Safe to drive. Fix it to stop fuel vapour loss and pass emissions inspection.
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