P0455EVAP System Leak Detected - Large Leak
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The evaporative emission (EVAP) system stores fuel vapour from the tank in a charcoal canister; a purge valve lets the engine draw it off, and a vent valve opens the canister to fresh air. P0455 means a large leak or that no vacuum builds up. Ford pulls the closed system down with engine vacuum and expects about −2 kPa within 30 s; after refuelling it sets P0457 instead. GM sets the code if 20 litres have been purged without reaching 2740 Pa tank vacuum (once per cold start, MIL after two trips). Saab's ME9 uses a pressure drop below 525 Pa. The code also covers blocked purging, for example a purge valve stuck closed.
- What you may notice
- Check engine light on (possibly a check fuel cap message)
- Possibly fuel smell
- EVAP readiness or emission inspection not passed
- Likely causes
- LikelyFuel cap missing, not clicked in or seal faulty (or capless flap)
- LikelyHose off or cracked (canister, filler neck, purge line)
- PossibleVent valve stuck open or purge valve stuck closed
- PossibleCanister or filler neck cracked or corroded
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €10 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.