Another little problem I have found is that the VNT actuator arm is seized solid, I've tried grips on it and a bit of force, but its stuck.
Judging from FiatECUScan's graph of expected boost pressures vs what the boost actually is, the VNT mechanism has seized in the safer way, and is not causing overboosting.
Also noticed my MAF has failed, so the ECU is sticking to a fixed figure, which should be set in the maps.
I'm thinking of either taking the turbo off once I get a day away from work, and stripping and cleaning the hotside myself, or perhaps using the innotec turbo cleaning kit I've seen about.
I've got quite good mechanical knowledge, coming from owning a renault, and doing an engine conversion, and also peugeot diesels, so I'm hoping it shouldn't be too much of a task.