Question

2012 Dodge Ram 4x4 with random misfiring now all the time and engine code P0305

Answer 1

P0305 Misfire number 5 cylinder

It would take one cylinder just to misfire and is capable of setting other cylinder to misfire, Take a look at the sparkplug and its electrode is not burned away. if it good you can swap the ignition coil of the number 5 cylinder to another good cylinder and if the misfire moves yo replace the ignition coil.