i want to know what is the advantage to removing the Air Control and Check Valve.



Also i have seen kits where they include a BAC cover plate, why would you remove that???? i thought that you need the BAC for warm up.

less **** in your engine bay mostly. When you get a full exhaust it will more than likely not have a cat, or a place to hook up your smog pump line. so then your smog pump becomes useless just sitting there turning. So you remove it and the valve and it leaves a large hole in your block. then you install the block off plate. get yourself a dual alt pulley and some new belts and your good to go.

but is there any kind of performance gain???

Well you're engine doesn't use power running the airpump so it will have a bit less resistance to its movement. Not enough to offset the benefit the pump provides to emissions though unless you really have given up on having a smog-legal setup.

nope!