[argon]

Hi, i drive a 323ci. I wanted to change the 4 o2 sensors, 2 before the cat and 2 after the cat. But my car does not have o2 sensors, or at least is not where its suppose to be. but the wire where you connect the sensors are there. Did 323ci come with this set up? The reason i wanted to change o2 sensors is it smells like the engine is running rich; and my fuel consumption is not so good. pls advise. thanks