Where is the oxygen sensor installed?
2 Answers
The oxygen sensor is installed before and after the three-way catalytic converter. Here are some introductions about the oxygen sensor: 1. Pre-catalyst oxygen sensor: The pre-catalyst oxygen sensor is a wideband oxygen sensor that can measure the oxygen concentration in the exhaust gas over a wide range, thereby inferring the air-fuel ratio in the combustion chamber. The engine control unit calculates the fuel injection time based on the oxygen sensor signal. 2. After the three-way catalytic converter: It is used to measure the remaining oxygen content in the exhaust gas. The engine control unit can infer the catalytic function of the catalytic converter based on the remaining oxygen content in the exhaust gas. To enable the sensor to enter the working state faster.
The oxygen sensor in a car is installed on the exhaust pipe, usually near the engine side, at the beginning of the exhaust pipe or near the catalytic converter in the middle. I've driven many cars, especially older models, where it's placed just behind the exhaust manifold. This allows it to promptly measure the oxygen level in the exhaust gases and send the data to the ECU to adjust fuel injection for combustion control. Proper positioning is crucial—if it's misaligned or loose, the signal may become inaccurate, leading to sudden increases in fuel consumption or engine shaking. This sensor is highly sensitive and prone to carbon buildup or moisture, which can affect fuel efficiency and emissions. After driving a certain mileage, it's important to monitor its replacement cycle—generally, it should be checked every 80,000 to 100,000 kilometers. Don't underestimate its small size; correct positioning ensures smoother driving and better environmental performance. I've personally experienced the check engine light coming on, only to find out it was due to a faulty oxygen sensor—replacing it immediately improved the situation. So, don't overlook regular maintenance.
