Will the engine shake if the oxygen sensor is broken?
2 Answers
The engine will shake if the oxygen sensor is broken. The function of the rear oxygen sensor in a car is to measure whether there is excess oxygen in the exhaust after engine combustion, converting the oxygen content into a voltage signal and transmitting it to the engine computer. This allows the engine to achieve closed-loop control targeting the excess air factor, ensuring that the three-way catalytic converter maximizes the conversion efficiency of hydrocarbons, carbon monoxide, and nitrogen oxides in the exhaust, thereby optimizing the conversion and purification of emission pollutants. If the oxygen sensor malfunctions, it can lead to unstable idling and excessive fuel consumption. A damaged oxygen sensor significantly reduces engine power, causes sluggish acceleration, and results in black smoke from the exhaust pipe. Generally, when the oxygen sensor fails, the engine warning light will illuminate, the engine will idle unevenly, the exhaust will produce a sputtering sound, emit a pungent odor, and fuel consumption will increase. You can use a diagnostic tool to check the voltage, which typically fluctuates between 0.1-1 volts, changing more than 8 times in 10 seconds. If the voltage fluctuates between 0.1-0.5 volts, it indicates a lean air-fuel mixture. If it fluctuates between 0.5-1 volts, it indicates a rich air-fuel mixture. If the voltage remains static between 0.4-0.5 volts, it means the oxygen sensor is damaged.
I've been repairing cars for over ten years and have encountered many cases where the oxygen sensor fails, and the engine does indeed shake. This is because the O2 sensor is responsible for detecting the amount of oxygen in the exhaust, sending signals to the ECU to control the air-fuel mixture ratio. If it fails, the mixture becomes unbalanced, either too rich or too lean. This causes the spark plugs to misfire or burn incompletely, leading to misfires and noticeable engine shaking, especially at idle. Besides shaking, common issues include increased fuel consumption and foul-smelling exhaust. At the repair shop, I often hear owners complain about unstable driving, and upon inspection, it's usually due to an aging or damaged oxygen sensor. I recommend immediately reading the fault codes to diagnose and confirm the issue. Replacing it with a new sensor will restore normal operation—don't delay, as it could affect other components. Regular maintenance, such as cleaning the sensor, can also extend its lifespan.
