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 EGTHDM CONTINUES TO SHOW GREATER THAN EXPECTED DATA SCATTER AND MARGIN LOSS INDICATION ERRORS, STILL SUSPECT. ACFT GROUNDED. REPLACED NR 1 ENGINE S1, S2, S3, AND S4 T49.5 PROBES. EEC TEST PASSES. REF AMM 77-21-01/401. NO EGT FAULTS IN HISTORY.