I dont think you understand the evap system takes air and fuel mix inside your tank and passes it thru an activated charcoal canister that absorbs the fuel vapor. That has nothing to do with the air that goes IN to your tank as fuel is consumed. That out side air has moistue that condenses out. ALL FUEL TANKS HAVE THIS IF THEY DIDNT THE DECREASING VOLUME OF FUEL WOULD CREATE A VACUUM. LOOK IT UP!!!The EPA has required EVAP systems since 1971. Any outside air would get "strangled" through the charcoal canister. But like I said, I haven't had any problems, and OP's car can only be tighter.