Boost goes up nicely to 0.5 bar at 3000rpm but then starts to drop to 0.3 bar starting 3000rpm until 4500rpm. After that it fluctuates about between 0.4 and 0.3 bar until 6000rpm. Any idea why? Boost leak?
Engine is 4g93 gdi turbo. All stock except k&n filter, stainless steel ic pipes, bov...