As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING OIL CHANGE, WITH THE RIGHT HAND LOWER COWL PANEL REMOVED, NOTICED THE AERODUCT HAVING EXHAUST RESIDUE ON IT. INSPECTED THE EXHAUST STACK AND FOUND THE LOWER FORWARD SEAM OF THE STACK TO BE SPLIT ABOUT 5 INCHES ABOVE THE MUFFLER ASSEMBLY. THE AREA OF THE SPLIT WAS DISTORTED AND BULGED.