What was found
DIAGNOSTICS REPORTED THE NR 1 ENGINE TREND DATA SHOWS A SHIFT IN EGT HOT DAY MARGIN ALL OTHER PARAMETERS NORMAL. EGT INDICATION ERRORS ARE SUSPECT PRI 2 ETOPS SIGNIFICANT SYSTEM. ACFT GROUNDED. ACCOMPLISHED EGT INDICATION SYSTEM TROUBLESHOOTING AND CONNECTOR CLEANING IAW AMM 77-21-00-140-801. NUMBERS BEFORE CLEAN, S1 - 228, S2 - 219, S3 - 222, S4 - 238. NUMBERS AFTER CLEAN S1 - 68, S2 - 35, S3 - 36, S4 - 86. SYSTEM OPS CHECK GOOD WITH ACTUATORS TEST, EEC TEST, AND RECENT FAULTS.