What was found
ON CLIMBOUT, HAD HEAVY FUMES IN REAR HALF OF AICRAFT, HAD WING AND ENGINE ANTI-ICE ON. INSPECTED APU/ENG INLETS AND ACMS FOR OIL LEAKS, PERFORMED WING AND NOSE COWL ANTI-ICE TEST, COULD NOT DUPLICATE. SUBSEQUENT FLIGHT HAD ODOR AGAIN, DETERMINED IT WAS FROM NR 2 PACK. REPLACED DIRTY WATER SEPARATOR BAG FOR NR 2 PACK, NO ODOR NOTED RETURNED TO SERVICE.