P0442 Fault Code

Long Description

The code P0442 is logged when a small leak in the evaporative emission control system (EVAP) is detected.

This does not necessarily mean that there is a small leak in the actual fuel system of the vehicle, only the EVAP. This code distinguishes itself from P0455, which represents the presence of a large leak.

The purpose of the EVAP system is to prevent fuel vapors from being released into the atmosphere. This is done to comply with emissions requirements and has been a requirement since the 1970s.

The EVAP system itself does not strongly influence the day-to-day operations of a vehicle.

This fault code can occur very easily, meaning it is often reported. Some of the most commonly reported manufacturers include Chevrolet, Jeep, Hyundai, and Suzuki.

Other Signs of This Problem

Issues with the EVAP system are notoriously hard to detect through symptoms alone. This makes it even more helpful to pay attention to the presence of the Check Engine light and subsequent fault codes.

Due to the small nature of this leak, it can be even harder to detect.

Looking for other EVAP-related codes can help determine the nature of the issue. These are fault codes like P0440, P0441, and P0456.

What Could Be The Problem?

There are several issues that could cause this issue. All of these are found within the EVAP system itself as it is a closed system.

One issue that causes the majority of these types of issues is a loose or faulty gas cap. If the gas cap is unable to properly create a seal and close off the EVAP system, this can cause a leak to be detected.

An actual leak in the EVAP system or fuel tank can also cause this fault code. All components need to be checked for leaks.

A faulty purge volume control valve or a faulty canister vent control valve can also lead to this p0442 leak code being logged.

Fixes

The appropriate fixes for P0442 are strongly related to fixing any existing leaks if present.

The first step should always be to check the gas cap for damage or faults. It should also be checked that the gas cap is properly fixed.

Finding leaks can require a specialist diagnostic tool called a “smoke machine.” This machine can make it much easier to detect even very small leaks in the system.

Any leaks in the fuel lines or components must be sealed.

Any faulty components in the system need to be repaired or simply replaced. The charcoal canister, canister vent control valve, and purge volume control valve are some of the most important components to check.

Seriousness

Fault code P0442 can be considered very low in terms of seriousness. There are no driveability changes and no risk of damage to yourself or the vehicle.

It should be fixed to prevent losses in the fuel tank, ideally within a few weeks.

It should be noted that a leak in the EVAP system can result in a failed emissions test. This means it should be prioritized if the vehicle is likely to be subject to one in the near future.