i have a 99 uk spec turbo. when driving the car it starts to hold back around 2500 to 3000 rpm you can feel it in the pedal once its kept in the turbo its fine. ihave green panel filter full stainless and a blitz boost controller. i have had it in the local subaru garage and the mechanic had it on the computer while i drove it and it showed no faults. i would be gratful if someone could help me out as it terrible to drive while driving at 60 mph
thanks

 

have you tried to clean out the boost solenoid do a search it will tell you how to do it just a tought mate hope it helps