As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT GATE, PRIOR TO FLIGHT, BOTH PACKS TURNED ON AFTER APU POWERED ON. EGT TOO HOT TURNED OFF RIGHT PACK. FUMES & SMOKE BEGAN FILLING MID TO AFT CABIN, TURNED LT PACK OFF. FOUND APU LEAKING OIL. APU CHANGE PLANNED. ACCOMPLISHED PACK BURNOUT PER WORK CARD 21-92-12.