As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED THE LEFT ENGINE HAD LOW OIL PRESSURE, BELOW GREEN ARC AT 1700 RPM. DEBRIS WAS FOUND IN THE OIL FILTER, FURTHER INSPECTION DISCOVERED THE STARTER ADAPTER SHAFT NEEDLE BEARING TO BE SEVERELY DAMAGED. THE ENGINE WAS REPLACED.