As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OIL PRESSURE FLUCTUATION ON CLIMB OUT, THEN DROPPED BELOW 25 PSI. RAN QRH WITH THRUST LEVER AT IDLE, PRESSURE STARTED TO INDICATE NORMAL. ACFT RETURNED, EMERGENCY DECLARED. R & R RT ENGINE OIL PRESSURE TRANSDUCER IAW AMM 79-31-05 (IPC 79-30-00 ITEM 35A). OPS AND LEAK CHECKS GOOD.