1999 Dodge Dakota 1999 Dodge Dakota misfires and pops

Hi I have a 1999 dodge dakota 5.2 4 wheel drive. It wouldnt start the other day, I cahnged plugs and it fired right up (correct gap) now it misfires, pops real loud, it ran great before it got cold, I used a scan tool it said misfireing on 6 cylinders so I started by unpluging the #2 plug wire it ran fine and stopped popping so I replaced the plug and wires and now its doing it again.I dont want to stick money into something that dont need to be fixed, my next thought is the cap and rotor. Anyone have any other thoughts if this dont work?