Gas fumes and pump sound from the gas tank

First posting on this forum. Look forward helping out my 4Runner family.

My 4Runner needs a little help right now, though.

Just finished a roadtrip through the hot Southwest. Started to notice that after driving more than 30 min. there is the smell of gas fumes coming from the gas tank. I turn off the truck and take a look...opening the gas cap (which is fairly new) and it vents positive pressure. There is also the sound of a pump operating and fumes are actively venting from the tank. The sound of the pump goes off after a few minutes and the smell and fumes stop.

Thinking that the charcoal canister needs to be replaced but having never dealt with one before I'm not sure if this is how it would show up. Any ideas?