I had the same as this with my car when I brought it mate, swear some people are just dicks, mine was running 1.3bar on stock internals and ct9, all it had was a FCD tucked up behind the glove box, so was running mega weak on full boost, found this pretty quick so reduced the boost to 0.75 jus before fuel cut,took the FCD off, and now its all running within standard specs, just makes me laugh that some people jus ain't got a fu@#Ing clue when it comes to these cars... An like addymk2 said see if the high low boost solenoid has been played with...