i just did the !wire mod, and it looks awesome....but it calls for you to take off a small vacuum hose about 8 inches to the right of the PCM

here is the picture:


so what does that do? the nipple on the end broke off, so i need to buy another one asap since i have work in the morning, and i dont know what its for and i dont want to go driving 30+ miles to work in the morning if its something important....

what is it?