P0440EVAP System
- 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. P0440 is the general code for a fault in this system without further narrowing down – leak, purge flow or component. Today most makers use the specific codes instead (P0441 ff, P0455–P0457, P0496); the GM and Ford tables of 2006–2023 do not contain P0440. It appears in VW code lists and in an FCA bulletin for the Alfa Romeo 2.0, fixed by software, where FCA calls it incorrect flow. What sets it is therefore manufacturer-specific; CARB requires purge flow and leaks to be monitored.
- What you may notice
- Check engine light on
- Possibly slight fuel smell
- Readiness or emission inspection not passed
- No change in driving
- Likely causes
- LikelyFuel cap leaking, loose or wrong
- PossiblePurge valve leaking or sticking
- PossibleLeaking or cracked EVAP hoses, canister or vent valve
- RareEngine module software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.