As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DESCENT, CREW REPORTED STRONG EXHAUST FUMES IN THE AFT CABIN. NO SMOKE WAS NOTED. CREW TURNED RIGHT PACK TO HIGH AND RECIRCULATION FAN TO OFF WITH NO CHANGE. FLIGHT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE APU OIL OVERSERVICED. REMOVED OIL TO PROPER LEVEL. OPERATIONAL CHECK OF APU NORMAL.