What was found
SEA FLIGHT NR 2322: POWER PLANT MESSAGE DISPLAYED ON ED AFTER BRINGING CONDITION LEVERS FROM START FEATHER TO MAX. MAINTENANCE INTERROGATED CDS AND FOUND FAULT CODE 242A&B ON THE NR 1 ENGINE. REMOVED AND REPLACED NR 1 ENGINE TQ B PROBE (PN 3047252-01) PER FIM 61-20-05 PG 227-230, AMM Q400 TASK 77-11-06-000-801 AND 77-11-06-400-801. THIS DID NOT FIX THE FAULT. REMOVED AND REPLACED NR 1 ENGINE PEC PER Q400 FIM 61-20-05 PG 227-230 AND Q400 AMM TASKS 61-20-36-000-801 AND 61-20-36-400-801. FAULT CLEARED AND DID NOT REOCCUR. PERFORMED POWER ASSURANCE CHECK OF THE NR 1 ENGINE IAW Q400 MTC NR 670005. OPS CHECK GOOD. NO FURTHER DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.