sti76

Hi everyone please can you help me ive had my sti 96 for around 6 weeks now and when i bought it was misfiring so ive changed the plugs and new coil packs ive changed and cleaned the boost solenoid and the airflow what happens is when under boost its hesitating must worse in 1st gear and gets must better in 2nd and as i go up the gear it goes the car boosts on 11psi and the turbo comes it at around 3800rpm not sure where to go from here ive tried the self test with the green wires under dash and no fault codes come up any help would be great