As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ODOR IN REAR CABIN DURING DESCENT, AND AT THE GATE WITH APU RUNNING. THE AIRCRAFT WAS GROUNDED. ACCOMPLISHED J/C'S 26L00021001, TROUBLESHOT THE CABIN AIR QUALITY. APU ODOR IN CABIN. DECONTAMINATED THE ECS. FOUND AN INTERNAL OIL LEAK ON THE APU. ALL REQUIRED PACK COMPONENTS CHANGED. REPLACED THE AFT CARGO TRIM AIR VALVE IAW AMM 21-43-51.