Will the engine malfunction light come on if the oxygen sensor is faulty?

[OAvery]

If the oxygen sensor is faulty, the engine malfunction light will come on. Poor performance of the oxygen sensor can affect the normal operation of the engine. Relevant information about the oxygen sensor is as follows: 1. Introduction: The oxygen sensor is used to detect the concentration of oxygen in the exhaust and sends feedback signals to the ECU, which then controls the increase or decrease of the fuel injector's fuel supply, thereby keeping the air-fuel ratio of the mixture near the theoretical value. 2. Function: The sensor measures whether there is excess oxygen in the exhaust after engine combustion, i.e., the oxygen content, and converts the oxygen content into a voltage signal transmitted to the engine computer, enabling the engine to achieve closed-loop control targeting the excess air factor. This ensures that the three-way catalytic converter achieves maximum conversion efficiency for the three pollutants in the exhaust—hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOX)—maximizing the conversion and purification of emission pollutants.

[DelJoy]

I've seen many oxygen sensor failure cases, and the light definitely comes on. The oxygen sensor is responsible for monitoring the oxygen concentration in the exhaust, helping the engine computer adjust the fuel ratio. If it fails, the computer won't receive the correct signal or detects an abnormality, and the fault light will activate immediately. I've often encountered this issue with older cars—sudden increase in fuel consumption, the car struggling to breathe, and upon inspection, it turns out to be a sensor problem. Delaying repairs can even damage the catalytic converter, costing more money and polluting the environment. So when the light comes on, it's best not to drive long distances. Quickly find a professional repair shop to read the fault codes and confirm the cause. After all, while the sensor is easy to remove and replace on the exhaust pipe, matching the correct model is crucial. Ensuring safe driving is a small investment with big returns.

[IanRose]

As a guy who loves tinkering with cars, a faulty oxygen sensor can indeed cause the engine light to come on. The engine computer relies on sensor data to balance combustion, and when it fails, it triggers an error and lights up the warning. I'd start by using an OBD scanner to check for codes like P0420 to pinpoint the issue before replacing it myself—there are plenty of online tutorials and tools are easy to find. Remember to disconnect the battery to avoid short circuits. Ignoring the light leads to faster fuel consumption and sluggish performance. Last time, I helped a neighbor replace a set of new sensors, and the light went off—the car ran much smoother. Don’t wait until a major repair is needed; saving costs is key.

[Craig]

Yes, the light will come on because the engine computer detects an abnormal oxygen sensor. When the sensor is faulty, the computer cannot receive accurate oxygen signals and will illuminate the warning light to alert the driver. If the issue is not repaired, fuel consumption may increase, potentially causing pollution and affecting the vehicle's inspection compliance. I've encountered similar risks before and promptly had it repaired. For safety reasons, when the light comes on, you should stop and inspect the vehicle immediately to avoid delaying repairs.