Intermittent boost limp mode story so far

[Karl88volvo]

Firstly - please comment- any feedback much appreciated!
Hi, the never ending volvo saga
on going problem Volvo v50 2.0d 2005 130k
EGR blanked at 100k
From 125k problems start
Intermittent boost and limp mode, P2263
Changed both TCV solenoids - no better
Changed fuel filter - no change
Cleaned Maf and IAT sensor - no change
Changed Map sensor - no change
Bad wiring to turbo actuator replaced - no change
Had a reconditioned turbo fitted £1000 - no change
Changed all vacuum hoses - no change
De-cat exhaust - no change

Car pulls like a train when its running well and may do so for mabye 3 days consecutively
Other times it may go into limp mode repeatedly - ignition off and on and its fine again or P2263 cleared with scan tool and its immediately fine again.
Other times it will have no boost until around 3500rpm

Doesnt appear to be loosing boost just doesn’t seem to create any, can’t find any leaks.

Any suggestions? Have i over looked anything? What can i try next?
By rule of elimination i must be able to track the culprit down surely? 🤷🏻*♂️