As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIAGNOSTICS REPORTS NR 1 ENGINE TREND DATA SHOWS A SHIFT IN EGT HOT DAY MARGIN ALL OTHER PARAMETERS NORMAL. EGT INDICATION ERRORS ARE SUSPECT. GROUNDED - YES. ACCOMPLISHED FMC CDU FAULTS TASK CARD 78273000 FOR ANY EGT SYSTEM FAULTS, NO FAULTS LOGGED IN RECENT AND HISTORY. FOUND CJ9 HARNESS CHAFFED. REMOVED AND REPLACED CJ9 HARNESS REF AMM 73-21-06, OPS CHECK NORMAL. ALSO ACCOMPLISHED EGT SYSTEM CONNECTORS CLEANING.