As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT FROM BCT TO CLE AIRCRAFT EXPERIENCED UNEXPECTED LOSS OF PRESSURIZATION. AIRCRAFT DIVERTED TO KSAV FOR EVALUATION. AIRCRAFT WAS INSPECTED AND A FERRY FLIGHT TO CLE WAS COMPLETED. IT WAS DISCOVERED THAT THE ECS MUFFLER HAD CRACKED ALONG A BEND LINE OPENING UP AND ALLOWING CONDITIONED AIR TO BE UNRESTRICTED. MUFFLER WAS REPLACED AND AIRCRAFT RETURNED TO SERVICE.