The parts illustration on the ford service manual just shows the whole hose including the box, and labels it Air Bypass Valve Intake Hose.. guess you can only assume the box is the valve itself.
Hmm. If it is hollow inside, then it seems odd to call it a “valve”. Could the actual valve be incorporated in the IAC? Obviously it is there for a reason but if its only purpose is to reduce intake noise somehow, then I would consider removing it and replace with a stainless braided hose. Since it is connected to the IAC, I have a feeling the “Air Bypass Valve Intake Hose” may have some effect on drivability.
I am looking for ways to clean up the engine bay. That’s the reason for my interest in the little black box. Thanks for your responses.
Another name for an Idle Air Control is Throttle Air Bypass. I'm sure the manual is referring to the IAC as the 'Air bypass valve'. I'm sure nothing negative could happen by removing the box, but don't quote me on that. My thoughts are that it's just there to prevent intake howl.