As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ABNORMAL ENGINE INDICATIONS NUMBER 2 ENGINE AT ALTITUDE AND IN DECENT LOUD NOISES/BANGING OBSERVED NUMBER ONE DROPPED OFF TO APPROXIMATELY 54 PERCENT. AT IDLE ALL INDICATIONS NORMAL. CONTINUED IDLE OPERATION UNTIL LANDING. EMERGENCY WAS DECLARED AND WAS NOT OVERWEIGHT FOR LANDING. **SUPPLEMENTAL REPORT REQUIRED** (OPEN)