What is the P0442 Code? Symptoms, Causes, and How Do I Fix It?

The trouble code P0442 appears on your engine control unit when there is a leak detected in the EVAP emission system.

You could have many possible reasons. This is all you need to know about P0442.

P0442 Definition

EVAP system leak detected (small leak)

What is the meaning of P0442?

If the P0442 code is displayed, it means that there has been a leak in your EVAP emissions system. The EVAP emission is a sealed fuel-gas system which then passes through the car's engine for environmental purposes.

A P0442 is an engine control code that will allow the unit to detect a leak.

This code is similar to P0455, so it means there is a little leak. If there's a large leak, the code p0455 is used.

P0442 Signs

The check engine light and other symptoms will be the only signs of a P0442 Code.

Here’re some possible symptoms of code P0442

Is the P0442 Code serious?

Extremely low – There is no danger for your engine to keep driving with the P0442 code.

In rare cases, your engine may run slightly less efficiently due to the leak. This is not only harmful to the environment.

The P0442 Code: Causes

A P0442 error code can be caused by letting your engine start at the station without the fuel cap. You may also have a leaky fuel cap, or an inoperable hose.

• Valves for vent control or bleed failures.
• Cap gasket damaged
• The charcoal canister is leaking.
• Leaking EVAP hoses
• Fuel tank leaks

Which repairs are possible to fix the code P0442

• Tightening the gas cap & remove the trouble code.
• Cap gas valve
• Replacing the EVAP control valve
• Replace EVAP hoses
• Replacing charcoal canister
• Replace Fuel tank

Common mistakes in P0442 diagnostics

Deep diagnostics are the most frequent mistake that causes P0442 trouble codes. Usually, this trouble code appears when you didn’t shut off your car while refueling it at the gas station or a faulty gas cap. This is the first thing you need to do before diagnosing your car.

Recommendations for Diagnosis

How do you diagnose the P0442 code?

1. Check for trouble codes by connecting your OBD2 scanner. After you have refueled, ensure that your trouble code isn't accidentally saved.
2. Check that the gas cap has been tightened and that the seals are in good condition.
3. The EVAP solenoid should be checked. Send power to the solenoid to check its function. Make sure it is sealed when it’s closed. Check the wirings to it and make sure the engine control unit sends + and – to it.
4. Turn off the fuel vent and push it toward the tank. You should seal it. If you find a leak you can use an EVAP smoking machine to easily put smoke in the tank.
5. You can remove any trouble codes by ensuring that everything is closed and the solenoid has worked.

Similar Trouble codes

Calculated Cost for Repair

These are examples of repair costs for the code P0442. These prices are inclusive of labor and parts. The prices do not include diagnostic costs.

• Gas cap replacement cost – 20$ – 80$
• EVAP control valve replacement cost – 40$ to 80$
• Vacuum hose replacement cost – 10$ to 80$

Common Questions Related to P0442