As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: ON DESCENT FLIGHT ATTENDANT REPORTED A BURNING WAXY/OILY ODOR IN THE AFT CABIN, NO SMOKE WAS NOTICED AND IT LASTED A WHILE AND WENT AWAY. MAINTENANCE FOUND OIL RESIDUE ON THE APU INLET AREA AND CLEANED THE INLET. A SATISFACTORY LEAK/ OPEATIONAL CHECK WAS ACCOMPLISHED.