What was found
ETOPS - MCDU'S DON'T MATCH WHEN IT COMES TO FUEL PREDICTION, TIME PREDICTION, AND VERTICAL PATH ERROR. FO'S MCDU APPEARS TO SHOW TIME: 4 MINUTES EARLIER, FUEL BURN: 400 MORE POUNDS, ABOVE DESCENT PATH: 400 FEET. REMOVED AND REPLACED FQIC PER AMM 28-42-34-04. NO DEFECTS NOTED OK FOR SERVICE.