Trying to put my airbox back in, and noticed on the back side of the ab, theres 2 hookups for vacume lines, one in the center and one to the left of that. I have a hose to connect to the middle one (crankcase vent tube i assume) but when I took the box off, i never noticed a hose hooked up to the other nipple. Only other hose i have free is my gas tank vent/overflow hose. Should i put it back as it was, or should i at least put a rubber plug on it??