Hey Amused2Death
Spot of bad luck your having there
There is an EGR cooler in the valley of the CRD
There is EGR piping behind the left cylinder head
There are three exhaust connections at the rear of the engine
Low boost could mean a bad charge pipe too
There's an o'ring on the aluminium tube that feeds the turbo
The plastic resonators on the front of the engine have been know to crack
Double check your turbo boost/piping/intercooler/piping connections
Hope that helps, oh and remember;
whilst it's OK to sleep with the dog,
never share his food