Ok could someone just tell me what would cause a misfire to switch cylinders? Ive had a p0300 come up then a p0302 and then a p0305. I had a friend from gm use a scanner a week ago and the only cylinders misfiring were 2 and 3. So whatever it is it seems to jump around. ICM maybe? Ive swapped it already but maybe that one was bad to?