Having some trouble with the cossie at the mo and need some advice if anyone can help,

Right the prob is when the bastard reaches around 15psi/ 1bar it hits a brick wall, you can hear wot sounds like wastegate chatter, can i also add it dosent always do it just about 90% of the time, sometimes it will pull right up to 26 psi and will fly like a rocket then you change gear and it will hit the brick wall again sending you nearly into the screen lol,

List of parts ive changed are 3 bar map, act sensor, actuator, and its just had a chip from MSD , spark plugs.

Helppp please as its really starting to bug me now

Many thanks,

Steve.