2000 mustang gt. Just swapped in an 04 explorer 4.6. Started up but very rough idle. Checked engine codes, turns out cylinders 4, 5, 6, and 8 are not firing which also happen to be the last 4 in the firing order. Double checked this with noid lights and the lights don't work with any of those cylinders but do work with the other cylinders. Checked voltage of misfiring cylinders and they do receive the 12 volts thus im thinking it has to do with the pcm not sending the ground signal to those cylinders. Hoping not to need a new pcm but at a loss on what to do next so any help would be appreciated. Thank you all in advance.