P0442 What does it mean?
Can you drive, what causes it and how it shows.
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Common codes
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.
Can you drive?
“Yes, you can drive”. This is the fuel vapour system: the engine is not at risk. Check the fuel cap first.
9,533trouble codes explained in plain words, free.
What causes it
The most likely cause comes first. Some you can fix yourself.
- 1Fuel cap loose, missing, or worn seal
- 2Small crack in EVAP hose
- 3Purge valve leaking
How it shows
Usually it shows like this.
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
In the app
Partly freeExplaining a trouble code is free: 9,533 codes, offline. With an adapter the app reads the code itself and tells you whether you can drive. A sample scan is free; unlimited scans come with VINARI+.
Common questions
What does P0442 mean?
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.
Can I drive with P0442?
“Yes, you can drive”. This is the fuel vapour system: the engine is not at risk. Check the fuel cap first.
What causes P0442?
Most often: Fuel cap loose, missing, or worn seal, Small crack in EVAP hose, Purge valve leaking.
How do I find out which code my car has?
Plug an ELM327 OBD adapter into the OBD-II port under the steering wheel and tap “Scan” in VINARI. The app reads the code, explains it and tells you whether you can drive.
Do I still need a mechanic?
Yes. The app tells you what is going on and how urgent it is; the final word belongs to the mechanic.
Other topics
Source: OBDex (CC0), VINARIUpdated 2 November 2026
