As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(M2ZR) FOLLOWING TAKEOFF, PILOT DETECTED AN UNUSUAL ENGINE SOUND ACCOMPANIED BY LOSS OF ENGINE POWER. PILOT RETURNED TO AIRPORT, LANDING DOWNWIND ON A TAXI WAY. INSP OF ENGINE REVEALED RT MUFFLER PN 1250251-16 BAFFLE/FLAME CONE ASSY. HAD COME LOOSE AND WAS OBSTRUCTING THE EXHAUST OUTLET. FURTHER INSP REVEALED LT MUFFLER ASSY. BAFFLE/FLAME CONE WAS ALSO LOOSE. REPLACED LT AND RT MUFFLER ASSY.