I got engine era code p0302 po442 p0303 P0304

Question

Where do I start engine running rough

Answer 1

Start with the misfire condition. because the misfire is cylinders 2 , 3 and 4 . what not showing is cylinder 1, if you can swap cylinder 1 ignition coil with the cylinder that is showing a misfire condition and see if the misfire moves then you would know it the ignition coil , if you allow the misfire condition to continue the lifer would collapse and the valve spring would just pop out of position.