What is the purpose of this hose on that side of the airbox? It connects to nothing.

 

That's the air pump relief. The ACV controls what happens with the air pump's air, and when it doesn't need the air for some emissions reason it dumps the extra to atmosphere. The air goes to a muffler in the airbox to quiet any noise, then out to atmosphere through that tube.

Dale

 

Ahh, I see. Thanks for clearing that up -- I learn something new everyday, hehe.

 

Yea, that hose goes nowhere. Took me by surprise also when I need to remove my airbox to install the ProfecB.

 

Is that the hose causeing the "Moo"ing sound, when removing the stock airbox? or is that a different hose ?

 

You got it! That's the "Moo" hose.