going to be a an air boost leak or the sensor itself
air / boost leaks can be:
boost pipes
turbo wastegate if old type with a short vac ram going to it
EGR sticking open
so cant follow your diagnostic tool .. forscan is best is you can see what the EGR is doing
im not sure how modern actuator would create a leak .. it could stick and not make enough boost .. has gearbox with plastic gears that strip and the actuator Variable Geometry mechanism on the turbo can stick. a sort of iris.
all the best.mark

