Read more about the EVAP purge valve.Ī crack in one of the EVAP hoses or lines or in the EVAP canister can also cause a small leak, but without testing equipment finding a small crack is very difficult.Īccording to the GM service bulletin, in some 2011-2013 Chevy, Buick and Cadillac vehicles the code P0442 might be caused by the leaking EVAP Vent Solenoid (CVS). The purge valve controls the flow of the vapors into the engine. Read more about inspecting a canister vent valve. A vent valve is located near the charcoal canister, usually in the back of the vehicle. The vent valve is normally open and closes when powered. The fuel cap sealing surface on the filler neck needs to be inspected for corrosion. If rust coming out of the fuel cap, or the fuel cap seal looks damaged, the cap must be replaced. The fuel cap needs to be inspected for cracks in the seal and other damage. However, we know that the three most common culprits for the code P0442 are the fuel cap, the vent valve and the purge valve (solenoid). Without testing equipment, diagnosing the code P0442 is difficult. To run the EVAP system leak test, the mechanics also use an advanced scan tool that can operate the components of the EVAP system and monitor the pressure or vacuum inside the fuel tank. Many automotive shops and dealers have a special device called " smoke machine" to test the EVAP system for leaks. rust damage of the fuel tank, filler neck or EVAP hose
cracked EVAP line or ripped EVAP rubber hose faulty vent valve solenoid (canister close valve) rust on the fuel cap sealing surface of the fuel filler neck
If the problem is caused by blockage in the EVAP vent valve or hose, the car might be difficult to fill with gas. In some cars, the warning about fuel cap being loose may also appear on the dash. In some cases, you might notice a faint gasoline smell when the car is parked in a garage.
With this code there might be no symptoms other than the Check Engine light. The code P0442 indicates that the engine computer (PCM) has detected a small leak in the EVAP system. As you drive and conditions allow, the engine computer (PCM) tests the EVAP system for leaks by monitoring pressure or vacuum inside the system. The purpose of the EVAP System is to prevent fuel vapors inside the fuel tank from releasing in to the atmosphere. Home > Check Engine light > P0442 P0442 EVAP System Leak Detected (Small Leak): causes, symptoms, diagnostic