As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EXHAUST STAINING ON THE OUTSIDE OF COWLING. DISCOVERED EXHAUST HAS BEEN PRESSURIZED AT EVERY ANNUAL SINCE INSTALLATION. CRACK WAS NOT EVIDENT IN AT THE LAST ANNUAL APPROX 90 HRS AGO. IT WOULD APPEAR THAT THE CRACK WAS CAUSED BY EXCESSIVE STRESS ON THE EXHAUST.