Error codes P0300, P0302 and P0304 2010 Buick LaCrosse

Question

Previous had a reported intermittent misfire Cylinder 2. Took to dealer and they could not find anything so they swapped the coil and spark plug wire with Cylinder 4 and now we have this combination P0300, P0302 and P0304. I am going to make a wild guess that we now have an intermittent misfire on cylinders 2 and 4. Thank, Bob