Tank venting and fuel vapours

P0442 Small leak in the fuel vapour system

By: Diagno editorial team · Updated: 2026-10-15

P0442 means: Small leak in the fuel vapour system. Fuel vapours from the tank are collected in a charcoal canister and burned in the engine. OK to drive, but have it checked soon. The repair usually costs about €10–300 in Estonia. The most common cause: fuel cap is loose or its seal is old.

Is it safe to drive?OK to driveOK to drive, but have it checked soon.

Typical repair cost€10–300parts and labour in Estonia

What it means

Fuel vapours from the tank are collected in a charcoal canister and burned in the engine. There is a leak in this system or a valve isn't working. It usually doesn't affect driving. The leak is small. Often the fuel cap seal or a cracked hose is to blame.

What could be wrong

1Fuel cap is loose or its seal is old
2Leaking hose
3Purge valve has failed
4Charcoal canister or its valve

What you can check yourself

Tighten the fuel cap until it clicks. Clear the code and see whether it comes back. You can do the simpler checks yourself.

How we fix it

We check the cap and its seal
We smoke-test the system
We replace the valve, hose or canister

Standard SAE description: EVAP System Leak Detected (Small Leak)

Want a definite answer?

Bring the car to our workshop in Estonia for diagnostics. We read the fault codes, test the sensors and tell you what is wrong. Repair price depends on the work involved, generally €45 per hour.

Book a diagnostic check

Questions

What does fault code P0442 mean?

Small leak in the fuel vapour system. Fuel vapours from the tank are collected in a charcoal canister and burned in the engine. There is a leak in this system or a valve isn't working. It usually doesn't affect driving. The leak is small. Often the fuel cap seal or a cracked hose is to blame.

Can I drive with code P0442?

OK to drive, but have it checked soon.

How much does it cost to fix P0442?

Roughly €10–300 in Estonia. The price depends on exactly what has failed and on the car.

How is P0442 fixed?

We check the cap and its seal. We smoke-test the system. We replace the valve, hose or canister.

Based on AI combined with our hands-on workshop experience and knowledge. This information is general and prices are approximate (Estonian workshop rates). The same code can mean different things on different cars. Only an inspection of the car gives a definite answer.