subaru impreza limp mode

[jayney 12]

hi, i have a subaru impreza 2ltr turbo 1997, the car is immaculate bought it last june but 5 weeks ago it put itself into limp mode, i did everything i could to try and solve the problem i.e changed and tested all components, did a compression test etc, in the end i gave in and sent it to a subaru specialist at fleetwood they said that within half hour of them having it they would solve the problem as they have the technology to sort it, well its been 4 weeks on tuesday since they had it and the bill is currently at about �450 and its still not fixed does anyone have any ideas, once i get it to 3000 revs it knocks the power down to limp mode no problem codes coming up from the ecu, has anyone had this problem before as i am baffled and at this rate will be broke, thanx in advance for any help x