Common Symptoms
The P0442 code usually doesn’t manifest itself in noticeable signs. That 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 a small EVAP leak event, it immediately turns the Check Engine Light on.
While the engine light doesn’t necessarily indicate the P0442 code, getting your car checked is a good idea.
2. Poor Gas Mileage Due to the EVAP Leak
Refilling at the gas station too often?
If the EVAP vent solenoid and EVAP purge solenoid can’t control the opening of their respective valves, it could lead to an EVAP leak and a drop in fuel economy.
Here’s how:
The EVAP canister stores the gas vapors so the engine can use them during combustion. When these valves don’t function, the vapors escape, leading to a lean air-fuel mix. This causes the ECM to overcompensate by injecting more fuel into the system, decreasing gas mileage.
You may also notice a fuel smell from the engine due to the leaking gas vapors.
3. A Failed Emissions Test or Smoke Test
One of the main indicators of the P0442 code is a failed emission test or a smoke test.
A smoke test uses a smoke machine to find hard-to-detect fuel vapor leaks. The smoke machine adds pressure and smoke to the fuel system, making small leaks visible.