Customer complaint about running rough missing firing, check engine, and exhaust smelling like rotten eggs. Codes P2178 System Too Rich Off Idle, also had code for system too rich at idle but don't recall the Code. It also had misfire codes for every cylinder. The history on this car is new plugs , all 4 ignition coils, and new PCV /oil separator Assem. First thing i did is to check for fuel present in the engine oil which I did. Next I removed all spark plugs to see if the injectors were leaking fuel into the cylinder and fuel going past the piston rings and into the crank case but the all cylinders looked dry. The only other way fuel can be keeping into crank case is the high pressure fuel pump.