Air Fuel Sensors - 2009 OBW 2.5 NT

My 2009 OBW 2.5 Non Turbo tends to stutter at stops, never stalls out just a sluggish stutter on power. I was considering the Air Fuel Sensors. There are two at the front of the vehicle. Left bank, right bank or first bank, second bank...not sure what they're called. Is there a way to determine which one might be bad...if any. Whenever I look the part up at online part stores it describes one required. The O2 sensor is near the cat....these aren't universal sensors are they? Am I just getting myself confused here?

Thanks