A friends v6 accord dies while driving.We have changed the main relay spark plugs battery and the problem still occurs any idea what else it could be?

 

have you tried changing the ignition cylinder? cause thats what happened to me and my accord. i replaced it and now everything is fine. never died on me once. also i think honda did a recall on these accords because of the iginition but im not sure. hopefully thats the issue.

 

ignition switch, check it out.