P04020 Code (2015 Accent GLS)
So I got this code for over a year. I just keep clearing it. I figured it was my gas cap so I bought a new one. When I clear the code it stays off much longer than it used to when I tighten down the cap. Also bought some Cat Clean and ran that through. It used to come on every 10-15 miles now it comes on every 40-50 or longer. Anyone know what may be causing this or what I need to do to fix it. I analyzed it with a ODB2 scanner and fed all the data into AI and it said it was fine.