As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENG ANTI-ICE VALVE ON TAXI. C/W NNC 3.3 CANNOT TAKEOFF REQUIRES HIGH THRUST CYCLED ENG ANTI ICE AND EICAS/ VALVE LIGHT DISAPPEARED CALLED DISPATCH & MAINTENANCE THEY SAID RTB A/C RETURNED TO GATE AND MTX GROUNDED A/C. MTX REMOVED AND REPLACED LEFT ENGINE INLET ANT-ICE VAVLE OPS CHECK NORMAL IAW B767 AMM 30-21-0 OPERATED ENGINE CHECK OK IAW B767 AMM 71-00-00 A/C REMAINS NO ETOPS.