OBD-II code · Powertrain (generic)
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.
Is it safe to drive with P0442?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyFuel cap loose, missing, or worn seal
- PossibleSmall crack in EVAP hose
- Less likelyPurge valve leaking
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.1–2 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Fuel Filler Cap, Evap Canister, Evap Purge Valve
Related codes
- P043FEVAP System Leak Detection Reference Orifice High Flow
- P0440Evaporative Emission Control System Malfunction
- P0441Evaporative Emission System Incorrect Purge Flow
- P0443Evaporative Emission System Purge Control Valve Circuit
- P0444Evaporative Emission Purge Control Valve Circuit Open
- P0445Evaporative Emission System Purge Control Valve Circuit Shorted
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.