As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE EGT FLUXUATES FROM NORMAL TO 70C ON EICAS AND ALTERNATE SYS. ACFT RETURNED TO STATION. ACCOMPLISHED FIM PROCEDURE 77-21 FAULT TREE 103, BLK 1,2,21. R & R LT ENGINE EGT JUNCTION BOX IAW AMM 77-21-02. OPS CHECKS NORMAL ON ENGINE RUN UP IAW ERH B767 01-01-1.