As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT TT: 145.7 HOURS. PILOT NOTICED EXHAUST FUMES IN CABIN. FOUND NR 1 EXHAUST GASKET BLOWN-OUT AND ATTACHING HARDWARE LOCATED IN BOTTOM OF COWLING. RIGHT HEAT SHROUD HAD SLID DOWN EXHAUST MUFFLER ALLOWING FUMES TO ENTER CABIN THROUGH HEATER. HARDWARE ON HEAT SHROUD WAS TIGHT. SB 97-78-01 WAS C/W AT 59.2 HOURS. SB 98-78-03 WAS C/W AT 131.3 HOURS.