I pressure tested my AFM when I thought it could be leaking...

It didn't leak at ~20psi...Although no pressure gauge was used...just listened for leaks.

 

I think Ahmet was referring to flow characteristics when he mentioned the AFM dealing with boost. It would seem that air flow sensed by the AFM would be different if it was positioned before the turbo like in the stock position as opposed to after the turbo in that set up...