What could be causing misfire?

What is your question?

Have a 2014 Ram 1500 with Hemi motor. It suddenly started missing, Now it won't idle (rough idle) slight chattering, spark plugs all changed except on 2 back cylinders. Changed 2 coil packs still doing same thing. Put a cam positioning sensor in. Codes are multiple cylinder misfire to rich fuel bank one and 2. Any Suggestions for what could be wrong.

What makes this problem better or worse?

Nothing,

How long has your 2014 Ram 1500 had this problem?

Just happened suddenly not able to drive it now