As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOW OIL PRESSURE LIGHT ILLUMINATED IN FLIGHT. A PRECAUTIONARY LANDING WAS MADE. ON SITE INSPECTION DETERMINED THAT A PIECE OF COTTER PIN HAD BROKEN OFF AND WAS CAUGHT IN THE PUMP. THE BROKEN COTTER PIN AND OIL PUMP WERE REPLACED. UPON RUN-UP, SYSTEM CHECKED GOOD.