As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIAGNOSTICS REPORTED NR 1 ENGINE TREND DATA SHOWS A SHIFT IN DELTA CRUISE INDICATIVE OF EGT INDICATION ERRORS. ACFT GROUNDED. PERFORMED T49.5 PROBE & EGT SYSTEM INSPECTION AMM TASK 77-21-200-801-F00. T49.5 S4 PROBE FAILED RESISTANCE CHECK. R & R T49.5 S4 PROBE. OPS CHECKED GOOD. IAW AMM 77-21-01 FOR T49.5.