As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COCKPIT ODOR - DESCENDING FROM CRUISE ALT OF FL400. STARTED GETTING A STRONG ORDER SIMILAR TO JET EXHAUST. IT SMELLED DIFFERENT THAN WHEN THE HEAT IS TURNED UP. REMOVED CLEANED INSTALLED ECS WATER SEPARATOR AND PERFORMED SATISFACTORY ECS DUCT BURN OUT THEN INSTALLED NEW ECS WATER SEPARATOR SOCK ALL WORK PERFORMED IAW TASK FORM TC-5XL-21-120902M AND AMM 21-51-00 NO MORE ODOR DETECTED AT THIS TIME