What was found
(CAN) ON TAKEOFF, THE PILOT REPORTED THE ACFT VEERING VERY HARD TO 1 DIRECTION, THE TAKEOFF WAS ABORTED. FURTHER INSPECTION REVEALED THAT THE RT ENGINE WAS ACCELERATING NORMAL UNTIL 30" MANIFOLD PRESSURE AND THEN DROPPING OFF POWER BACK TO IDLE. MAINTENANCE DISCOVERED A FAULTY DIFF PRESSURE CONTROLLER, THE ENGINE WAS CHOKING OUT BEING RUN TO RICH AS A RESULT OF THE WASTE GATE NOT CLOSING. THE CONTROLLER WAS REPLACED AND THE ACFT WAS FOUND SERVICEABLE.