What was found
(CAN) SHORTLY AFTER TAKEOFF, CREW WAS ALERTED TO AN ENG INDICATION PROBLEM. DIVERSION BACK FOR MTC INVESTIGATION. RESOLUTION IAW FIM TASK 77-00-00-810-852A ITEMS 4A-1 CARRIED OUT, NIL FAULTS. CHANGED T12 SENSOR FOR ENG 1 IAW AMNM 73-21-40-000-040. IDLE RUN CARRIED OUT.