How to Determine if the Oxygen Sensor is Damaged?
4 Answers
You can determine if the oxygen sensor is damaged by observing the color of its tip. If the tip is white, it indicates that the oxygen sensor has been contaminated by silicon to a certain extent and needs to be replaced promptly. If the tip is brown, it means it has been contaminated by lead and also requires replacement. However, if the tip is black, it is mainly due to excessive carbon buildup, and simply cleaning it thoroughly will suffice. Relevant information about automotive oxygen sensors is as follows: 1. The automotive oxygen sensor is a critical feedback sensor in the electronic fuel injection engine control system. It is a key component for controlling vehicle exhaust emissions, reducing environmental pollution caused by vehicles, and improving the fuel combustion quality of the engine. Oxygen sensors are installed on the engine's exhaust pipe. 2. The oxygen sensor is used in the feedback control system of electronic fuel injection devices to detect the oxygen concentration in the exhaust and the richness or leanness of the air-fuel ratio. It monitors the theoretical air-fuel ratio (14.7:1) combustion within the engine and sends feedback signals to the computer.
There are quite a few methods to determine if an oxygen sensor is faulty. I've personally encountered this situation before – while driving, I noticed unstable idling, with the car shaking like it was drunk, and a sudden spike in fuel consumption leading to noticeably more frequent refueling. I usually make it a habit to observe the exhaust; if black smoke comes out of the tailpipe or there's a pungent odor, those could be signs of an oxygen sensor malfunction. Don’t ignore the warning lights on the dashboard, especially the engine-shaped one. Using an inexpensive OBD scanner plugged into the car, you might retrieve fault codes like P0130 or P0135, which directly point to oxygen sensor issues. I also recommend regularly inspecting the sensor's physical condition to check for loose connectors or oil buildup, as these can affect performance. For safety, it’s best to get a professional diagnosis at a repair shop to prevent minor issues from escalating into major problems that could impact driving efficiency and emission compliance.
I found the simplest method is using an OBD scanner, which any regular car owner can operate. I bought a scanner for just a few dozen dollars - after starting the car, plug it into the diagnostic port under the steering wheel and press a button to read fault codes. If it shows oxygen sensor related codes like the P0170 series, that basically confirms the issue. While driving, you can also watch for abnormal symptoms like sluggish acceleration, lack of power, or fluctuating idle RPM, which are common indicators. Another important clue is unexplained increase in fuel consumption - last month I spent over a hundred yuan extra on gas because of this. I recommend developing good driving habits and not ignoring vehicle warning signs - addressing issues early can save significant money.
When the oxygen sensor malfunctions, the most significant sign is a sharp increase in fuel consumption. I've personally experienced this, with fuel consumption rising by one or two points per hundred kilometers, making my wallet feel empty much faster every time I refuel. If you notice the engine sound getting louder, poor exhaust flow, or unstable idling while driving, you should also suspect a sensor issue. A more direct indicator is the check engine light—when it turns red or yellow, quickly connect an OBD tool via a mobile app for diagnosis. A faulty sensor can have a major impact, so regular engine maintenance is crucial to avoid carbon buildup contaminating the sensor.
