random multipule cylinder missfire
It only missfires when you put load on it IE; passing or going up hills, but other times runs smooth. The engine has about 175,000 on it, has new plugs, wires, coils, and icm. It does have some codes the random multipule cylinder missfire, o2 sensor after the cat, and egr flow insuficent. Next week the cat is going to be replaced with straight pipe and egr deleted, those have been planned for a while. What could cause this ? fpr ?