can someone please help i had been booting my car quite hard runnin 1 full bar of boost (have recently fitted a new dump valve ) and after 10 mins the car is drivin and sounds fine but im only pullin 0.5 bar at full throttle now can anyone help ????

 

Limp mode. Try reseting the ECU. Look for fault codes too..

 

As dan said.
Worth checkng Scoobypedia | Trusted knowledge for everything Subaru | Scoobypedia browse for how to check for fault codes and how to reset the ecu.