gas cap

I want to get my boyfriend (who owns a 2013 Jeep Wrangler) a customized gas cap for his jeep. I found one from a website called "Skull Krushers" but I couldn't find many reviews about the shop online and I'm not sure if a regular gas cap is supposed to be more or less expensive (it's $48.99 on...

2003 cherokee, code0455 large evap leak, replaced gas cap,checked what I could find of hoses. I have a weird slight knocking/tapping noise coming from the area between the gas cap and the rear bumper when the truck is running. Could this be causing the light to come on? Should I be worried...