2012 Countryman S here and as the title says, I've changed all 4 coil packs and all 4 spark plugs. I bought the delphi packs and the 95770 NGK plugs. I am getting misfires on all 4 cyclinders codes P0301, P0302, P0303 & P0304. I am not getting any other codes. What's my next step?

 

High Pressure Fuel Pump?? It can cause the same symptoms you're seeing. They did extend the warranty on the pumps due to high failure rates, yours may still be covered.

 

My daughter bought a 2011 countryman S also I got nominated to work on it as dealers are 300 miles away had same problem with 1 2 3 4 cyl. Changed plugs,coil packs,injectors,low pressure fuel pump (thinking filter might be plugged) now its just #4 keeps cutting out fuel inj to #4. Found a site telling you how to reset Permanant DTCs that hasn't worked either.This other article says that it will not reset until emissions are cleaned up so computor can see it. This was part of EPAs standards as of 2010. Getting balder every minute i work on this thing