I am a new Dodge owner, I've always wanted a heavy duty truck. I got a 2012 3500 Leramie, I am trying to get familiar with the two what looks like oxygen sensors on th exhaust. Judging from their appearance and the cannon plut, they are wide band.

What do they control? Are they similar to gas O2 that reads the exhaust stream and adjust AFR? Is the such thing as "open and closed loop" in a diesel engine? Thanks in advance.