Oxygen Sensors Read the Amount of Unburned Oxygen in the Exhaust
The O2 sensors located in the exhaust manifolds provide the essential feedback for the fuel control loop that regulates the air/fuel mixture. On V6, V8 and V10 engines, there is one O2 sensor in each exhaust manifold. On four and straight six engines, there is usually only one O2 sensor in the exhaust manifold.