P0496EVAP System High Purge Flow
- 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. P0496 means vapour flows into the intake although the module is not purging – usually a purge valve that leaks or sticks open. GM and Saab seal the system after a cold start with the engine running; if tank vacuum exceeds 2491 Pa for 5 s, the code sets (fuel 10–90 %, MIL after two trips). Ford, which replaced its old code P1450 with P0496, also sets it for excessive vacuum during the leak test, for example with a vent valve stuck closed. Hard starting right after refuelling is typical.
- What you may notice
- Check engine light on
- Hard or long starting right after refuelling
- Rough idle, rich fuel trim
- Hissing vacuum when opening the fuel cap
- Likely causes
- LikelyPurge valve leaking or stuck open (charcoal dust in the seat)
- PossibleVent valve stuck closed or vent filter or line blocked
- RareVapour line kinked or blocked
- RareTank pressure sensor reading wrong
- 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: €50 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.