As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING A CHECK FLIGHT AFTER MX, PILOT AND MECHANIC NOTICED AN ERRATIC OIL PRESSURE INDICATION ON THE NR 2 ENGINE. OIL PRESSURE WOULD GO FROM ZERO TO NORMAL, WITH RAPID FLUCTUATIONS. NO OTHER ENGINE PARAMETERS WERE AFFECTED. PILOT ELECTED TO RETURN TO DEPARTURE. FOLLOWING FLIGHT, OIL PRESSURE TRANSMITTERS WERE MOVED FROM LT TO RT AND SL510-79-02 WAS PERFORMED UPON INSTALLATION. IT WOULD APPEAR THAT REPERFORMING SL510-79-02 CORRECTED THE FAULT.