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P0442 is a diagnostic trouble code (DTC) for "Evaporative Emission Control System Leak Detected (Small Leak)". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
P0442 is a diagnostic trouble code (DTC) that is seen when a evaporative emission control system malfunction is present. This code may be seen with other EVAP system codes.
P0442 is present in vehicles that have a small leak in the EVAP system. The ECU carefully monitors the EVAP system for any leaks or irregularities, when a small leak is detected the ECU set a Check Engine Light to be displayed on the dashboard.
The Check Engine Light being present on the dashboard.
Some vehicles may exhibit a slight drop in gas mileage with the EVAP leak
Hooks up a scan tool to the vehicle's DLC port and checks for any codes present
Examines the freeze frame data associated with the code which shows the circumstances that were present with the vehicle at the time of the malfunction
Clears the codes and test drives the vehicle
Performs a visual inspection of the EVAP system, looking for any obviously cracked or broken components, and loose or damaged EVAP lines
Checks for cracks in the fuel tank or charcoal canister
Inspects the gas cap for proper fitment and condition, then tests with a gas cap tester
Uses a scan tool to monitor tank pressure and confirm if a leak is present
Tests the EVAP system solenoids and valves with scan tool
Performs a smoke test on the EVAP system, looking for smoke that indicates a vapor leak
Qualified technicians should have little problem diagnosing P0442 as long as all steps are followed in the proper order and none are skipped.
Commonly, the gas cap is the cause of P0442, if the gas cap is overlooked it can waste time and energy diagnosing other components.
The P0442 generally has no adverse symptoms other than the Check Engine Light being present. When this code is seen, it means that the EVAP system is leaking fuel vapors into the atmosphere. A slight dip in fuel economy may be noticed with this code.
Professional level tools make diagnosing the P0442 leak much easier and accurate. An advanced scan tool that allows access to live data and control of the EVAP system is very helpful when dealing with the P0442 code or any EVAP code in general.
Some vehicles have the ability to be commanded with the scan tool to test the EVAP system for proper operation of all components, and can be used to help isolate which part of the system the fault or leak lies.
Since they are fuel vapors, most of the EVAP leaks are much smaller than the eye can see. A smoke test is performed to find hard-to-detect fuel vapor leaks. This is done by using a specialized smoke machine that pressurizes the fuel system and adds smoke so that small leaks will be visible.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.