My '05 5.4L starting misfiring a couple weeks ago. Ran the codes and it said cylinder 1 misfire. Ran it again a week later and it said 7 cylinders were missing. I confirmed that with another code reader.

I've read a lot on here and am ready to replace all the coils, plugs, and wires to make sure I fix the issue. My question is, is there anything else that could cause almost all my coils to go at once? Something electrical? How can I test that?