What was found
ABOUT 5 MINUTES INTO FLIGHT, NOTICED A SLIGHT SMOKY ODOR & A MIN LATER, FA SAID SHE SMELLED SMOKE. SIC ALSO SMELLED SMOKE. WAS A STRONGER TOWARDS ZONE 3 & IT WENT AWAY & CAME BACK. SMELLED LIKE A CAMP FIRE SMOKE, BUT FA SAID IT SMELLED LIKE A CHEMICAL. NOT A STRONG ODOR & NEVER WENT TOTALLY AWAY. RAN A/C SYSTEM ON APU BLEED AIR WITH MAXIMUM HEAT SELECTED IN AUTO MODE, NO UNUSUAL ODORS NOTED. RAN SYSTEM IN MANUAL INCREASING TEMP SIGNIFICANTLY BUT STILL HAD NO ODOR. PERFORMED A HIGH-POWER RUN WITH TEMP MAXED IN AUTO & NO ODOR. RETURNED TO RAMP & SHUTDOWN ENGS, LEFT APU RUNNING WITH TEMP IN MAX AUTO. BEFORE SHUTTING APU DOWN, LOOKED AT BLEED SYNOPTIC PAGE & NOTICED ENTRY DUCT TEMP WAS 70 DEGREES C. PERFORMED TRIM AIR VALVE OPS CHK, & DUCT TEMP SENSOR OPS CHK, NO DEFECTS NOTED. TOOK ACFT OUT FOR ANOTHER HIGH-POWER RUN WITH NO DEFECTS. COULD NOT DUPLICATE HIGH TEMP IN ENTRY DUCT OR ODOR. REPLACED ENTRY DUCT TEMP SENSOR E105. REMOVED THE SUSPECTED BAD DUCT TEMP SENSOR E105 & INSTALLED A NEW TEMP SENSOR E105 & OPS CHKD GOOD IAW AMP TASKS BD700-A-J21-21-21-00AAA-520A-A & BD700-A-J21-21-21-00AAA-720A-A .