Smoke coming out of the gas cap

I have been getting EVAP codes P0441 and PO455. I put my smoke machine on and there was smoke coming out of the gas cap. I went to the local Toyota dealership and got an OEM gas cap for my car. That didn't solve the problem, smoke was coming out again. So I think it is the fuel neck gas filler hose. I been having a problem finding one for my car. I have a 2013 Toyota Corolla that was built in Mississippi. The VIN number is 5YFBUEEXDP197201. First of all do you think my diagnosis is correct and were can I find the part for my VIN number?