What was found
WHILE ACCOMPLISHING T/C 78273000, FOUND NR 1 ENGINE ECONOMIC FAULT 73-31371, UPPER EGT SECTOR READING HIGH. ACFT GROUNDED. PERFORMED FIM 73-11 TASK 801 UPPER EGT SECTORS READING HIGH. VERIFIED DISCREPANCY NR 1 ENGINE SHOWS FAULT 72-31371. INSPECTED T49.5 READINGS, FOUND S1=90.43, S2=45.75, S3=49.60, S4=112.27 STATIC. REMOVED AND INSTALLED NEW S4 EGT PROBE REF AMM 77-21-01. ACCOMPLISHED NR 1 ENGINE ELECTRONIC ENGINE CONTROL TEST REF TABLE IN AMM 71-00-00-800-811-F00. SYS CKS NORMAL. AFTER EGT CLEANING REF AMM 77-21-00, HARNESS CHECK REF AMM 70-70-01-200-801-F00, NEW T49.5 READINGS, S1=39-.5, S2=18.79, S3=21.10,S4=42.94. ALL READINGS ARE WITHIN LIMITS.