What is the function of this?
 

Hi all. What exactly is this part and it's function?
(6 port backpressure hose mount )

That part operates your 5th and 6th port actuators. At ~3500rpm, there's supposed to be enough backpressure to make the actuators open the 5 and 6 intake ports. Without it, your top-en will seem to be uninspired and laggy. The actuators are on the passenger side of the car, attached to the lower intake manifold, just above the exhaust manifold; you should be able to (with a little effort) operate the actuators by hand (push down), and have them return to their "off" position by themselves.

The actual mount is where the backpressure/air injection hose connects to the catalytic converter or the lower intake manifold.

Great, thanks for the good explaination black.