Nissan Oxygen Sensor

WHERE IS THE CAR OXYGEN SENSOR LOCATED?

Newer vehicles will have more than one sensor?one ?upstream” and one ?downstream” of the catalytic converter. The upstream sensor will be on the exhaust pipe, closer to the engine, while the downstream sensor is situated closer to the muffler; the idea is to fine-tune the input the engine computer receives by getting two readings. V6 and V8 cars and trucks with dual exhaust will have sensors for each exhaust pipe (four sensors).