Volvo Repair: s80 Power Loss, throtle body, diagnostic check

Question
Dear Sir,
My father and I are both proud owners of two 2.9 auto S80  Volvos. My car is fine but my father is experiencing severe power difficulties with his 2003 model. When he presses down on the accelerator pedal the car looses power and appears to choke. A diagnostic check on his car hasn't shown any fault codes so we have been told that the next step in identifying the problem is trial and error which could cost thousands of Euros. And advice on where to start would be greatly appreciated. I dont know whether it is relevant but the car had the pedal sensor replaced under warranty in 2004.

Answer
Finbar, not to be rude but owning an S80 is nothing to be proud of.  These cars are nothing but problems waiting to happen.  Anyway, from what you are describing, it sounds likfe 2 things.  1 is the air mass meter and the other is a throtle body issue.  These cars have a factory recall on the throtle units.  The dealer is supposed to replace them for free.  Roger