The truck turned on the MIL one day after work. Code PO456 (Leak in EVAP, small). I decided to check underneath first and saw a small, almost hairline crack in the hose downstream of the filter coming off the vacuum tank. I popped it off to take a closer look, and when I spun it around to look at the side that you couldn't see when it was attached, I saw this:
Stopped in to the stealership and of course you can't buy just the piece of hose with the 90 degree bend, you have to buy the whole "harness". I didn't even bother asking how much that was. I stopped at an autoparts store but they don't have anything in a 14mm ID. So, I just wrapped it up real good with electrical tape. A few local trips and 250 miles of towing and the code hasn't come back.
Just something to check if you're getting a vacuum leak in EVAP code.