Im almost done with my b16 swap in my 1990 civic hatch. Everything is looking good, all my heater/coolant hoses, as well as my vacuum lines are all hooked up, I was fidling with my exhaust and i found a hose coming out of the firewal on the passenger side almost on the bottom. Its about 1/2-3/4 inch in diameter. I have no idea what this is. I have everything hooked up! Any Ideas.....? Thanks