As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK. SMOKE AND FUMES IN CABIN. FOUND WATER SEPARATOR BAGS DIRTY. REMOVED AND REPLACED BAGS AND RAN BOTH ENGINES AT 75 PERCENT N1 FOR 10 MINS. NO SMOKE OR FUMES NOTED. REPLACED WATER SEPARATOR BAGS AGAIN FOR MX CONVENIENCE OP''S CHECK GOOD PER MM.