As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED AN OIL HAZE AND ODOR IN THE CABIN WITH THE APU RUNNING AND THE AIR CONDITIONING PACKS ON, AT GATE. MAINTENANCE FOUND APU LUB MODULE DPI POPPED AND LEAKING OIL. DPI INDICATOR AND FILTER REPLACED. DUCT BURN-OUT PERFORMED AND COALESCER BAGS REPLACED. NO FURTHER SMELL. AIRCRAFT RETURNED TO SERVICE.