As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED LEFT ENGINE NOT PRODUCING FULL POWER AT 2500 FT, 28" MP AND 2515 RPM. MAINTENANCE INSPECTED AND FOUND THE LEFT REAR EXHAUST PIPE FLANGE BROKEN LEADING TO TRANSITION BLOCK. THE PART WAS REPLACED WITH NO FURTHER DEFECTS NOTED.