As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PROPELLER CHANGE ON LEFT ENGINE, A SERIES OF CRACKS WERE FOUND ON THE INBOARD EXHAUST FLANGE. THE FLANGE IS A PART OF THE POWER SECTION, SO FIELD REPAIR WAS NOT POSSIBLE. THE AFFECTED POWER SECTION WAS REPLACED WITH A SERVICEABLE POWER SECTION. A POSSIBLE CAUSE FOR THE CRACKED FLANGE MAY HAVE BEEN THE RESULT OF OVERTORQUING THE HARDWARE ATTACHING THE EXHAUST STACKS TO THE FLANGE. (X)