The factory running of your missing hose, like KM says, goes into a spot in the back, rear of your right air filter box. There's a hole there that you just slide the hose through. Its put there so the open end of the hose can be in a "dead" air-space. A neat trick, that is highly suggested for you to do, is to trim that end of the hose at a slight angle so as to prevent an otherwise "flat" end from ever being able to wiggle over and bottom out up against the airbox and prevent any flow of air. The cut angle ensures that the hose is always open.