What where the finding of the log?
Is the ecu asking for the load and the hardware not giving it, ie N75 duty cycle 95%+
I would not fit a new turbo yet, not until you know 100% what this issues are. We use scopes to look in to the turbo via the lambda boss and the DV location.
I have also found the D valves to leak and bleed boost off.
Should all N75 duty cycles request 95% + And then start declining as boost is applied
