okay guys, just got done basically rebuilding my 00 civic si since i bent 8 vaulves :/ okay well i get my car back andwhen im checking everything out i notice on the back of the intake manifold is an open line with nothing on it. its sucking air so i know its a vacumm line. but idk what to hook up to it i found this diagram and it says its something to do with the cruise control. well my cruise control isnt their, and i dont want to just leave it open. if i try to cap it off it makes my car idle at like 450 rpms like it bearly stays running. what should i do? Thanks!

 

circled in red