What was found
EXIT STACK OF MUFFLER SEPARATED FROM THE MUFFLER. SUBMITTER STATED APPEARS WELDS MAY NOT HAVE BEEN 'NORMALIZED' CAUSING A BRITTLE AREA AROUND THE WELD. THIS WAS AN FAA-PMA PART. ENGINE SHOWED NO SIGNS OF VIBRATION. EXHAUST EXITED THE MUFFLER INTO COWLING, GASCOLATOR, AND CARBURETOR AREA.