1kD Engine looses boost when up to temperature

[Benjahma]

Hello my Toyota 1KD loses turbo pressure when it gets up to temperature. I get a few, full power pulls and then the boost slowly drops off whereby it's then feels like a normally aspirated engine. I have changed the injectors, throttle pedal assembly boost pressor sensor and throttle body and it does the same thing. Diagnosis shows no error readings. The strange thing is I have had the car for a year it was like this for the first 4 months then one day it fixed itself and was fine for the last six months and now it has gone back to behaving the same. If anyone has had similar symptoms and could help diagnose I would be extremely grateful thank you

[dave g]

I would be looking at the turbo and step motor