As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) AS THE AIRCRAFT DEVELOPED TAKE-OFF POWER, THE PILOT NOTICED ABNORMAL ENGINE NOISE AND ABORTED THE TAKE-OFF. AN INSPECTION OF THE ENGINE REVEALED THAT THE LEFT REAR EXHAUST MANIFOLD HAD SEPARATED FROM ITS MOUNTING FLANGE. EXHAUST MANIFOLD REPLACED WITH PART NO. 20-7800-01-07.