As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GE DIAGNOSTICS REPORTS NR 1 ENGINE TREND DATA SHOWS A SUDDEN SHIFT IN EGT HOT DAY MARGIN. ALL OTHER PARAMETERS NORMAL. EGT INDICATION ERRORS ARE SUSPECT. ACCOMPLISHED EEC BITE TEST NR 1 ENG REF T/C 78273000. NO RECENT FAULTS OR FAULT HISTORY LOGGED. REPLACED CJ9 HARNESS AT NR 1 ENG REF MM73 21 06. OPS NORMAL.