What was found
DURING THE CLIMB OF THE FLIGHT FROM IAD TO EWR, THE CREW REPORTED A STRONG EXHAUST SMELL ENTERED THE CABIN FROM BOTH FLOWS. THE CREW DONNED OXYGEN, RETURNED TO IAD, AND LANDED WITHOUT INCIDENT. MAINTENANCE PERSONNEL SECURED A CLAMP ON THE ACM DUCT TO THE WATER SEPARATOR. AN ENGINE RUNNING OPERATIONAL CHECK WAS SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.