I've noticed that whenever I open up the gas cap to put fuel in the tank, it makes a hissing noise. Once the gas cap is off, there's sometimes a small blast of fuel odor when it's completely off. I've read a few different forums and have seen different answers... Some say it's normal, others say it's not.

There is an exhaust leak coming from somewhere, and whenever I turn on my A/C or heat, there is a faint gasoline smell. The other two cars I have owned have never done this, even when it got really hot out. When I do put it back on, I make sure it's on tight enough too.... I tighten it to three or four clicks.

Is this usually a normal thing? There aren't any CEL codes or anything if that helps.

 

Mine does the same thing, but it's because I don't have a charcoal canister. It's the black cylinder under the cruise control unit (if you have one), mounted on the firewall. Check the lines leading to and from it, maybe?