Hi, A few things to check, firstly the MAP sensor on the back of the inlet manifold, remove it and if its very dirty give it a gentle clean with some brake cleaner, the egr being closed should help keep it clean but its worth a try.
Check the small vacuum hoses to the turbo actuator for splits, if the are original its worth changing them for silicone, a meter is only a few quid on ebay, you need 3mm.
Unplug the MAF sensor and see if it drives better, you will get a fault code which you can clear afterwards if you have multiscan.
Edit, also check the vacuum hoses to and from the actuator solenoid on the front panel.
Last edited by JON156VELOCE; 29-01-14 at 16:27.