As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 4023 - SHORTLY AFTER TAKEOFF, CAPTAIN NOTICED RT ENGINE OIL PRESSURE FLUCTUATION ASSOCIATED WITH AURAL WARNING AND MASTER WARNING PANEL INDICATION. AIRCRAFT RETURNED TO FIELD WITHOUT FURTHER INCIDENT. MAINTENANCE SERVICED RIGHT ENGINE OIL LEVEL, CONDUCTED ENGINE GROUND RUN. ALL ITEMS OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.