As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX-IN CLIMB NOTICED OIL PRESSURE #2 ENGINE AT 45 PSI. REDUCED NP TO 1050. OIL PRESSURE WENT UP TO 55 PSI. A MINUTE LATER DROPPED TO 50 PSI. REDUCED POWER TO FLIGHT IDLE. NH WAS STILL ABOVE 75%. CREW DECIDED TO RETURN TO PDX. REMOVED AND REPLACED #2 OIL PRESSURE TRANSMITTER AND OIL PRESSURE/TEMPERATURE INDICATOR. GROUND RAN ENGINES FOR 10 MINUTES HIGH TO CRUISE SETTING. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.