As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXHAUST VALVE IN THE NR 9 CYLINDER NR 2 ENGINE FAILED CAUSING ENGINE TO RUN ROUGH. FURTHER INVESTIGATION FOUND METAL CONTAMINATION IN THE OIL SUMPS. THESE METAL FRAGMENTS WERE DETERMINED TO BE FROM PIECES OF THE DAMAGED VALVE. IT WAS THEN DECIDED TO REMOVE THE ENGINE FOR FURTHER INSPECTION AND THEN REPAIR.