What is this?

[GALLERY=]

Can someone tell me what this is for please, it’s currently held together with supper glue, and where i can get one?, part number? Also could it be responsible for my black smoke problem?, have checked i-cooler pipes, replaced fuel rail sensor as that was showing on code reader and changed a under fuelling injector with a brand new one, and it still looks like im shoveling coal into the bloody thing

That's a non return valve.

Any leaks in the vac pipes will reduce the amount the turbo can boost, if there's insufficient vacuum to drive the vanes.