As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUEMS/BURNING ODOR COMING THROUGH THE PACKS. NOTICABLE IN TH FLIGHT DECK ADDED SMOKE/ODOR FORM LINGERING ODOR FROM TAILPIPE FIRE ENTERED CABIN VIA PACK INLET AND OPEN DOORS WHILE PARKED AT GATE.AFTER APPROX 20 MINUTES CABIN NO LONGER HELD SMOKE ODOR. STARTED APU AND RAN PACKS PER 21-00-00-800-803 AND PERFORMED FIM TASK 21-00 TASK 830.