From what I read it could be the gas cap, not tight or not sealing. Also found info on possible hoses:
1 - inside drivers side of frame where the evap fuel line (top line) turns to hose and then connects near the fuel rail.
2 - under the drivers side of the hood, bottom of two black cylinders one is the LDP and the filter i believe. (between master cyl and coolant res.)
3 - under the drivers side of the hood, big black box (evap canister i believe) (right next to coolant res. ) to test valve . (green cap connected to a few hoses)
if you dont see anything, check over the whole evap system. all those hoses around the canister (black box) and the cylinders. youll probably end up finding something there.