The one on top is for the airpump, but I am wondering about the one on the bottom. It goes into the lower manifold. Do I need a filter on it? I dont recall every having one on there. I have a fighters garage intake system btw.

 

the bottom one goes to the intake I believe. I could go look but im lazy today . But im pretty sure its the intake.

 

dude just unbolt it and blank up the holes if you have eliminated your airpump thats what i did and my car runs fine

 

The bottom one should go to the air pump, IIRC. The top one is the air pump relief hose. It's the infamous "hose to nowhere". If you are keeping the airpump and leave that open, it will make a "mooo" sound. You can cap it and put a few holes in the cap to dampen the sound (old picture of my engine bay from 2003):

http://mahjik.homestead.com/files/FD...3/MVC-002F.JPG

If you are removing the airpump, you can leave it open or cap it. Eventually, you should remove the whole ACV system if you are removing the airpump.