Common symptoms
Engine code P0442 usually doesn’t manifest itself in noticeable signs. That being said, it does exhibit a few common EVAP code symptoms that you could look out for, like:
1. An Illuminated Check Engine Light
It’s almost impossible to physically detect an EVAP leak. So when the leak detection pump in the exhaust system suspects an EVAP system leak event, it immediately turns the Check Engine Light on.
While the engine light doesn’t necessarily indicate trouble code P0442, it’s a good idea to get your car checked.
2. Poor Gas Mileage Due To The EVAP Leak
When the EVAP vent solenoid and EVAP purge solenoid don’t open as they should, your gas mileage might be negatively affected. The vapors in your car used in combustion will get vented via the EVAP canister, using up some of the fuel that usually goes towards burning.
You may sometimes also notice a fuel smell coming from the engine due to the leaking gasoline vapor.
3. A Failed Emissions Test Or Smoke Test
One of the main indicators of code P0442 is a failed emission test or a smoke test.
A smoke test is performed to find hard-to-detect fuel vapor leaks. This is done by using a specialized smoke machine that adds pressure to the fuel system and adds smoke so that small leaks will be visible.