Over boost is when your boost goes beyond its set value, for some reason.
For safety, in the ecu there is a built in safety device called fuel cut, its purpose is to cut fuel when boost exceeds a pre set boost figure.... only thing is fuel cut is not good, especially if continuesly used..
When you get mapped, the mapper has to raise the point at which Fuel cut cuts in for him to safely rise the boost on your car.
Thats why stand alone boost contollers are a real disaster and a complete turn off for me if buying a car.
