No pressure when removing gas cap

I noticed this problem a while back and purchased a new gas cap from Toyota. Now 6 months later it failed inspection due to the same problem. They made me buy a new cap and passed it without checking it. Whew. How can I fix this??

 

Does the tank always release pressure when taken off? I am having a gas smell with my '05 Tacoma; it smells around the gas cap. Truck not throwing codes.... bought a new gas cap from Autozone, didn't fix the problem. I was told by a mechanic that the newer vehicles don't release pressure, but I have my doubts. The way I understand it is that it should release pressure but not vapors because it passes through the canister first. When I take off the old cap and now the new one, no pressure is released. Is this normal?

 

Totally normal. If you pull the cap off and look inside and up there are 2 holes at the top of the fuel filler neck where pressure is vented. That's why you are supposed to keep your truck shiny side up - to prevent fuel leaks through those holes.