As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING SCHEDULED MAINTENANCE EVENT THE COCKPIT MUFFLER ASSEMBLY WAS FOUND SPLIT OPEN. THE MAINTENANCE VENDOR REMOVED THE DAMAGED MUFFLER P/N 12845096-001 AND A NEW MUFFLER WAS INSTALLED. OPERATIONS CHECKS SATISFACTORY. NOTE: THIS IS A COMMON DAMAGE FINDING FOR THE COCKPIT MUFFLERS ON THE LEAR 45 AIRCRAFT.