hey guys theres a vacum line going to the inside of my drivers side fender and i was wondering what its for? thanks

Its for your cruise control. There's a large ball down there that the cruise control gets its vacuum from.

i don't have cruise control

It also controls the vacuum for the HVAC vents.

its the vacuum tank that asically serves to act as a buffer to smooth the vaucuum out for all your acc. It also acts as a sorce for vacuum. Basically like a capacitor. I took mine off after the nipple snapped off. The vacuum accesories seem to work fine w/o it.