standard ebv pipe, when blitz ebv fitted

I have been tinkering today and when i fitted my blitz afew months ago i was thinking about the standard ebv piping. On the top of the ebv there used to be a pipe (now blocked off, it sits right on the top and can see it easy, not the 2 underneath as there on the blitz solenoid) Does this still need to be fitted into the induction system somewhere so the ecu can tell what the boost is. I am not sure if the ecu uses this to tell the boost or just the amount of air being pulled through the maf.
If the ecu does still need the top pipe to be fitted then what side effects would i get.

Thanks Ash

This is the pipe comming out of the ebv?? The ebv is inactive if you have a EBC - blitz in your case.

Ross