2004 4.7 misfiring

Any advice appreciated. 2004 4.7 started misfiring on three cylinders last weekend. Thought it could be bad gas. Bought some fuel treatment and it cleared. Ran fine all week and just started again.

 

Maybe coil or spark plugs

 

Check your battery/alternator...these cars do really weird things when the voltage is low. Also, you say 3 cylinders precisely...did you pull the codes? Change the ignition coils from the suspected bad cylinders with those from suspected not bad cylinders. Check the plugs while you're at it.

 

Three at once is weird, it's rare enough for 1 coil to go bad. Are they neighbor cylinders in a row, like 1,3,5 or 3,5,7?

When was the last time you did plugs and more importantly where did you buy them if you did?

Say it is cylinders 1,3,5 ... if you swap coil packs with cylinders 2,4,6 does the problem move to cylinders 2,4,6?

 

Knowing which cylinders is super important. Especially if it might be fuel related. Also, does it miss fire as it runs or is this just on startup? And codes. Always love some good DTC codes.