P0442
Evaporative Emission System Leak Detected (Small Leak)
A small leak (typically equivalent to a 0.040 inch / 1.0 mm orifice) has been detected in the EVAP system. By far the most common cause is a fuel cap that is loose, missing, or has a worn seal.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
What we see in the workshop
ON FORD ECOBOOST
A small EVAP leak on a car in Dubai is very often a perished seal or a cracked line hardened by heat. We smoke test rather than guess.
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Common causes
Ordered by how often each turns out to be the cause.
- Fuel cap loose, missing, or worn sealCommon
- Small crack in EVAP hosePossible
- Purge valve leakingLess likely
Parts involved
- Fuel Filler Cap
- EVAP Canister
- EVAP Purge Valve
P0442 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.