As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTS FOUL SMELL IN THE AIR CONDITIONING SYSTEM AT LOW ALTITUDES. REMOVED WATER SEPARATOR ON LEFT PACK, SEPARATOR CLEAN. CLEANED RESIDUE IN OUTLET OF COMPRESSOR REHEATER, RAN PACKS WITH APU AIR AND WITH ENGINES AT PWR. NO ODOR NOTED AT THIS TIME.