What do you mean by "turbo waste gate is still set right?"
The 2.5 Turbo is quite different to the 2.8 Turbos....the 2002 Service Manuals describe how it works. I have a 2002 Export CRD.
I have always found that I get better performance if I block one of the thin tubes on the small black solenoid near the Turbo. This solenoid has an electrical connector on it which would give you an error code if you disconnect it but what I have done is I pull off the outer pipe...screw a small screw into the exposed male plastic tube to block it and fit the loose rubber pipe over the screw head so it all looks normal.
This was a tip from Papaindigo from Spain many years ago!