99 Civic D16Y8

Has anyone ever heard of an Air Flow Assist Sensor? It is threaded into the thermostat housing. I'm trying to figure out what it does and how the vacuum lines run.

i believe you are talking about the idle adjustment screw?

Nope. It is some sort of thermal vacuum switch that threads into the thermostat housing. I'm trying to figure out where the vacuum lines should run.

it goes into the thermostat housing with two ports coming out of it for vacuum? has a big long bolt that screws into the thermostat housing right behind it?

anyways, as for vacuum diagrams, this is the ultimate source.

http://forums.clubsi.com/showflat.php?Cat=0&Number=5045087&an=0&page=0