saab 9-3 turbo chokes when engine gets hot

Question

i have a saab 2002 9-3 aero turbo and i have had this problem when he gets hot he will somehow choke, u step the gas and the turbine does not kick in and he chokes, i have changed the turbine and adjusted the throttle body and nobody seems to know what this might be i have had many garages look at him, allso if you switsh him off and start him again he will run for couple og seconds normal it is really weird and he only shows a computer code for the catalytic converter, when the turbine was changed to whole system was flushd out, be the turbine did not actsualy go se started leaking oil, any help would be great