I have a Subaru Impreza. It gives me a P0442 code. It is a small Evap emissions leak. How can I be sure it is not the gas cap?
The gas caps are really common for the P0442 code. A gas cap costs like eight bucks. Get another gas cap and put it on and pray that it’s that. Because if it’s not that, it is generally time to call a mechanic. You have to put a smoke machine on. The EVAP system has a test port where you put the smoke machine on and then you check for leaks. You also need a dealer-level scan tool, so you can open and close various sections of the EVAP system to find out where the leak is. It’s very complicated stuff. So, get a new gas cap and put it on. And if that is not the problem, have the Check Engine Light diagnosed and repaired by a certified mechanic.