As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE OIL QUANTITY DECREASED TO 3 QUARTS IN CRUISE. OIL PRESSURE AND TEMPERATURE NORMAL. SUPPLEMENTAL DATA UPDATE OIL FILTER WAS REPLACED AT DEPARTING STATION DUE TO A FILTER BYPASS MESSAGE. AT MSP OIL WAS FOUND LEAKING AT THE OIL FILTER HOUSING COVER. IT WAS REPORTED THAT THE O-RING WAS DETERMINED TO BE TOO SMALL AND WAS THROWN AWAY. ANOTHER O-RING WAS INSTALLED AND THE ENGINE CHECKED OK.