Oxygen Sensor: Description and Operation

The oxygen sensor, located in the exhaust manifold or turbo outlet, produces voltage when exposed to oxygen present in exhaust gasses. The sensor produces a low voltage when the air/fuel mixture is lean and a high voltage when the mixture is rich. On 1984-87 models, the voltage signal is transmitted to the logic module which signals the power module to trigger the fuel injector. On 1988-89 models, the voltage is transmitted to the SMEC, triggering the fuel injector. On all models, the injector adjusts the mixture accordingly.