What the OBD-II code p0442 means

Fault code P0442 – a step-by-step guide to diagnosing and fixing it

The meaning of error code P0442 – Evaporative Emission Control System Leak Detected (small leak)
P0442
Search your trouble code

P0442: causes, symptoms and repairs

The meaning of fault code P0442

P0442 is registered when the powertrain control module detects a small fuel vapour leak in the evaporative emission control (EVAP) system, activating the check engine light. When the vehicle is switched off, the module tests for leaks by closing the control valves and thereby sealing the system. If the pressure is not maintained, it indicates that there is a hole or crack somewhere. This DTC is triggered for small to medium-sized leak holes with a diameter of around 0.02” - 0.04”.

Possible causes

  • A faulty purge flow solenoid or valve vent control solenoid. For example, the valve components may be affected by the gradual build-up of charcoal from the canister, carbon deposits and other impurities, causing them to wear or jam. Vapours may also be able to leak through due to damaged seals in the system.
  • A leaking charcoal canister or fuel tank leak. Cracks may start to appear and parts can corrode over time.
  • A loose, damaged or missing fuel cap of the car. Without a proper cap, the vapours will be able to escape through the filler neck.
  • Holes or cracks in the EVAP hoses. This can occur if the parts are not installed properly or are incompatible with the vehicle.
Symptoms of code P0442

  • Activation of the check engine light
  • Decreased fuel efficiency
  • A fuel smell while the vehicle is stationary
  • An increase in emissions
  • A rough or erratic idle
Recommended repairs

  • Check the DTCs using a diagnostic scanner to verify which faults have been detected by the control unit. P0442 may be accompanied by codes P0440, P0441 or P0446, which usually indicate a solenoid malfunction or canister leak.
  • The solution to the fault may be as simple as replacing the cap on the fuel tank in the car. Check the cap for signs of damage and make sure it is tightened properly. It might be a good idea to try replacing it anyway, especially if the component is quite old. Once you have done this, you can reset the DTCs to see whether this error reappears.
  • Inspect the hoses for cracks holes or signs of deformation, and install new parts if required. Replace any broken seals. Some holes or leaks may not be visible and will require a more advanced method of detection. They can often be detected using a smoke machine.
  • You can test the purge flow solenoid for technical faults with a multimeter. The resistance value should usually be somewhere between 22.0 ohms and 30.0 ohms. Sometimes vent control solenoid or purge valve leaks can be detected with a simple blow test.
Frequently Asked Questions (FAQ)

What does the code “P0442” mean?


It indicates that there is a small leak in the EVAP system, detected due to a loss of pressure.

What causes this?


Common causes include a loose or damaged fuel tank cap, defective control valves, or a leaking canister or hoses.

How can I get rid of this DTC?


It can be cleared using an OBD2 scan tool or by disconnecting the negative battery terminal to restart the onboard computer. However, if it reappears, the fault should be properly identified and fixed before erasing the DTC from the computer’s archive one more time.

Can I still drive my car if this occurs?


This fault should not cause any serious driveability or safety issues. However, we still recommend that you get the vehicle checked as soon as possible to avoid further damage.

Cars the fault code P0442 is most commonly found on

Fault code P0442 - Evaporative Emission Control System Leak Detected (small leak) can occur with any car but is most often found on the following cars:

  • Dodge: Caravan
  • BMW
  • Chevrolet
  • Ford
  • VW

If you get the code P0442 on your car, make sure that the diagnostics are carried out correctly and the error is still relevant. Check for symptoms associated with the problem and explore options for resolving it.

What to do if the fault code p 0442 appears

Most viewed car repair videos

  • Error p0442: a step-by-step diagnosis and repair guide
    How to change front wheel bearing on MERCEDES-BENZ M W163 TUTORIAL | AUTODOC
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change fuel filter BMW 3 (E90) [TUTORIAL AUTODOC]
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change Front wheel bearing on VW GOLF 4 TUTORIAL | AUTODOC
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change a rear brake pads FORD FOCUS 3 TUTORIAL | AUTODOC
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change pollen filter / cabin filter on AUDI A6 (C6) [TUTORIAL AUTODOC]
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change rear brake discs and brake pads on PEUGEOT 307 [TUTORIAL AUTODOC]
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change fuel filter NISSAN X-TRAIL T30 TUTORIAL | AUTODOC
  • Error p0442: a step-by-step diagnosis and repair guide
    How to change front wheel bearing TOYOTA YARIS XP10 TUTORIAL | AUTODOC
Want to get more useful information?

Ask questions or share your repair experience on the car forum. Subscribe to updates so you don't miss out on new guides.

Everything you need to know about the code P0442
Tips from AUTODOC CLUB
View more
  • Life hacks for the code P0442
    TOP 5 mistakes during DIY oil change | AUTODOC tips
  • Fast fixes for the OBD2 code p0442
    5 car interior cleaning mistakes | AUTODOC tips
  • The most common causes of code p 0442
    How to reduce fuel consumption | AUTODOC
  • Advice on what to do about the error P0442
    How to remove scratches from car plastic | AUTODOC tips
Install the AUTODOC CLUB app!
Your personal car expenses manager, maintenance tips, reminders about upcoming appointments and service intervals, DIY repair instructions – all this on your phone.
QR-code scan for AUTODOC CLUB app
Scan

To download the app:

  • - scan the QR code
  • - download from App Store
  • - download from Google Play
Autodoc CLUB App icon
Your profile is your personal assistant.

It can track car expenses, keep a car log and replacement schedule, and save favourite materials, notes and documents