What was found
(CAN) FOLLOWING AN UNEVENTFUL TAKEOFF AND CLIMB THE PILOT OBSERVED MAIN OIL PRESSURE (MOP) EXCEEDING OPERATIONAL LIMITS INTO RED ZONE WHILE IN CRUISE. AFTER UNSUCCESSFUL ATTEMPT TO REDUCE MOP, THE PILOT ELECTED TO ACCOMPLISH AN IFSD AND RETURNED THE ORIGIN AIRPORT WHERE HE MADE A SUCCESSFUL SINGLE ENGINE LANDING. CFIRST IS TROUBLESHOOTING WITH THE CUSTOMER. APEX AVIATION MECHANIC (CUSTOMER REGULAR CONTRACTED MRT SERVICE PROVIDER) IS ON THEIR WAY.