As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NEW STUDS AND THRU BOLTS OF OFF ON FINAL APPROACH, THE RT ENGINE STARTED RUNNING ROUGH FURTHER INVESTIGATION REVEALED THAT THE NR 4 CYLINDER EXHAUST WAS CRACKED. THIS WAS CRACKED BECAUSE THE NR 4 CYLINDER THRU-BOLTS BROKE WHICH ALLOWED OTHER HOLD-DOWN STUDS TO BREAK WHICH ALLOWED THE CYLINDER TO PARTIALLY SEPARATE FROM THE CRANKCASE.