TD4 2005 turbo BOOST PRESSURE CONTROL

Hi was wondering if anyone can help me I have a 2005 TD4, which has recently had fuel issues, which ive ive now worked out is the dreaded under rear wheel arch fuel pump starting to fail, but whilst I was investigating all the various fuel managment sensors, I found a turbo vent pipe which runs from the brake servo to what i belive the Turbo pressure control valve (its tucked under behind the egr) , which was split I replaced but noticed that there are 3 connectors for pipes on the Turbo pressure control valve , the one I replaced and the one that goes to the EGR vacum and then theres one with nothnig connected to it , my question is should this have a vent pipe connected to it or is it just some kind of breather, Also is it worth fitting a EGR blanking Adaptor does it really make that much difference to low end rev performance with out effecting the cars MOT emissions, Many thanks Guys n Gals