As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE IN FLIGHT PILOT EXPERIENCED POWER AND RPM LOSS WITH SUBSTANTIAL VIBRATION, EMERGENCY LANDING ACCOMPLISHED. FOUND #1 CYLINDER EXHAUST VALVE STUCK OPEN AND #3 CYLINDER EXHAUST VALVE STICKING. #1 CYLINDER EXHAUST PUSHROD FOUND BENT.