I know this hose goes into a evap canister thingy on my 300 but on my 1jz swapped 400 it's out in the open, should it be plugged or does it go somewhere? You can smell fuel out of it

 

As long as it doesn't effect the engine performance which I think it doesn't you shouldn't really have a issue. For the smell you can get a charcoal canister from the junkyard and set it up in there. Just make a bracket of some kind and bolt it up to that threaded hole on the right fender. If you running a open down pipe if you haven't finished the exhaust keep that hose away the gas will ignite. You can try a breather filter like for valve cover gases ,but I don't know how much that will help.