As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) OIL PRESSURE AND TORQUE FLUCTUATION IN FLIGHT NECESSITIATED ENGINE SHUTDOWN OF #1 ENGINE. POST FLIGHT INSPECTION FOUND AN "O" RING ON THE OIL TRANSFER TUBE AT THE "C" FLANGE WAS WORN FLAT AND LEAKING, CAUSING OIL TO LEAK ON THE EXHAUST CAN.