A rich air/fuel mixture is being discussed. Technician A says oxygen content in the exhaust will be high. Technician B says the O₂ sensor voltage will be high. Who is correct?

Question

Quizplus · Accepted Answer

Technician B is correct because a rich air/fuel mixture will result in a high voltage signal from the oxygen sensor (often referred to as O2 sensor or lambda sensor). This is because the sensor detects a low level of oxygen in the exhaust due to the excess fuel, leading to a higher voltage signal indicating a rich condition. Technician A is incorrect because a rich mixture will have low, not high, oxygen content in the exhaust.

A Rich Air/fuel Mixture Is Being Discussed