I have a 3.4 V6 in my '96 4Runner. After I shut it down it makes an intermittent "buzzing" noise out of the EVAP box. If I crack the gas cap it goes away. If it sits for awhile in the sun it starts making the noise again. I'm sure it's pressure related, but how do I fix it?

 

$20 part at the dealer that goes between the EVAP box, and the fuel tank. I have a picture of it on a piece of paper (not digital, sorry). The dealer should know what you need though...

 

Most of us just live with the noise but if you're dying to fix it then just do a search on YT for "EVAP buzz" or "EVAP buzzing" and you'll find all the info you need to remedy it.