Hi, I have a check engine code PO442 and PO445. I replaced the gas cap to no avail. Wondering how to check the EVAP valve solenoid( and it's location) and the best way to check the vent hose on the tank(does it require dropping the tank?). I also have been getting gas smells in the cabin from time to time too. What could be leaking and where, in order for the smell to come inside? I recently did the timing belt and water pump too. Need help locating the related components too.

Help is greatly appreciated!

1998 S70 GLT with 208,000 miles