As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NUMBER 1 ENGINE OIL FILTER BYPASS LIGHT CAME ON WITH OIL PRESSURE INDICATING 43 PSI. LIGHT REMAINED ON AFTER REDUCING ENGINE THRUST. *S/D* EXCESSIVE CARBON FOUND IN MAIN OIL FILTER. CLEANED CARBON FROM PRESSURE SWITCH AND REPLACED FILTER. RECHECKED FILTER AFTER 12 HOURS AND NO CARBON FOUND.