I've read a number of OLD posts looking for the physical location of the fuel tank pressure sensor for various models (foresters, WRXs, etc.) while trying to troubleshoot a P045x code (P0453 in my case) and no one ever seems to have found it.
I FOUND IT! And I would imagine its in a similar spot on other models
It is located on the rear passenger side above the upper control arm. if you have skinnier arms you can just reach it.
If I solve my P0453 code I will post my solution. Fingers crossed.
Hope this information is of use to someone since it really would have helped me when I started to off-and-on look for this thing days ago since all diagrams in the manual are SO vague about its location.
Best I can do until I can get my img.nasioc.com account working is this imgur link (you're on your own to get it working though. on PC you can highlight the link and right click then "go to 'url' ")
https://imgur.com/gallery/5PT3lts
[pictures coming soon.... STILL having issues]