My 2003 Honda Civic EX Coupe recently started misfiring on all cylinders, throwing codes P0300-P0304. I took it to the dealership and they told me I had a bad ELD and that when they diagnosed my car it threw a Honda specific code P1298. Honda wants to give me a new fuse box for $495 but if i get a new ELD and put it in myself is it likely to solve the misfiring problem, or are the two problems unrelated? I understand that the ELD changes the alternator voltage based on the electrical load on the car. Can it be telling the alternator to run too low and not create enough voltage to make nice sparks, or do I have deeper problems?