Measures residual oxygen in the exhaust so the control module can trim fuelling toward the ideal mixture. Upstream sensors drive fuel trim; downstream sensors grade catalytic converter performance. Each carries an internal heater so it reaches operating temperature within seconds of a cold start rather than waiting for exhaust heat.
Also known as: o2 sensor, o2, lambda sensor, lambda probe, lambda, ho2s, heated oxygen sensor, air fuel ratio sensor, afr sensor, wideband sensor
Referenced by 326 codes
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The oxygen sensor — the lambda sensor — is what closes the loop. Without it the engine management system is running a model of what it thinks is going into the engine. With it, the...
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