As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT 3526, F/A COMPLAINED OF GAS ODORS COMING FROM CABIN. MAINTENANCE COMPLETED PACK BURN AND VERIFIED CONTAMINATION COMING FROM APU AIR SYSTEM DEFERRED APU PER MEL 49-00-1 (C) TRANSFERRED TO DMR MXC NOTIFIED 6425. MAINTENANCE REPLACED APU P/N 4501690A, S/N SPE977509 IAW APU GANGE JOB CARD REF JOB CARD AND 409, 172209 FOR DETAILS. REMOVED FROM DMR MXC NOTIFIED.