Fuel cap not tightened or with a worn seal; Small crack in an EVAP hose or connector; Leaking purge or vent valve; Cracked charcoal canister; Leaking filler neck seal.

How much does it cost to fix P0442?

Usually 30–350 € at an independent workshop in Europe, depending on which part is at fault.

P0442 EVAP system small leak detected

What P0442 means

The engine computer periodically seals the fuel vapour (EVAP) system and checks that it holds pressure or vacuum. P0442 means it found a small leak, roughly the size of a pinhole. It does not affect driving, but raises evaporative emissions.

P0442 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.

At a glance

Severity: Low
Typical repair cost: 30–350 €
Workshop time: 0.1–2 h
Repair difficulty: Easy
DIY possible: Yes
Check engine light: Yes
Affects emissions test: Yes

Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.

Symptoms

Check engine light on
Faint fuel smell, especially after refuelling
Car drives normally
Technical inspection failure for emissions

Common causes

Fuel cap not tightened or with a worn seal
Small crack in an EVAP hose or connector
Leaking purge or vent valve
Cracked charcoal canister
Leaking filler neck seal

Can I keep driving with P0442?

Yes, you can keep driving. Tighten the fuel cap first; if the code returns after several days of driving, have the system checked.

What to check first

Check the fuel cap seal and tighten it until it clicks; clear the code and drive for a few days
Inspect EVAP hoses and connectors around the canister and tank
Test the purge and vent valves for leaks
Have a smoke test done to find a leak that cannot be seen

Related codes

Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
Updated: 2026-10-24