As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RED BOX ON ENG #1 EGT DISPLAY. GROUNDED - YES. FOLLOWED B737-900 FIM 71-06 T ASK 805 STEP (F)(2). ACCOMPLISHED EEC BITE ON #1 ENGINE REF FIM 73-00 TASK 801. NO RECORDED ENG OR EGT FAULTS. EGT PROBES S1-S4 TEMPS ALL WITHIN ACCEPTABLE LIMITS. ACCOMPLISHED FIM 71-06 TASK 805 STEPS F.(3)-F.(5) FOUND #1 ENG PRSOV LEAKING, REMOVED & REPLACED REF B737-900 AMM 36-11-04. HPT BLADE BORESCOPE ACCOMPLISHED & NO DEFECTS NOTED. TEST 5 POWER ASSURANCE CHECK ACCOMPLISHED & FOUND ENG OPERATION IS SATISFACTORY.