What are the functions of the front oxygen sensor and rear oxygen sensor?

[VanCameron]

The front oxygen sensor is mainly used to detect the oxygen content in the exhaust gas, while the rear oxygen sensor is primarily used to check whether the three-way catalytic converter is functioning properly. Below is an introduction to the front and rear oxygen sensors: 1. Installation position: The front oxygen sensor is generally located behind the exhaust pipe, and the rear oxygen sensor is usually positioned behind the three-way catalytic converter. 2. Function: The front oxygen sensor can detect the oxygen content in the exhaust gas and then send the signal to the ECU, which can adjust the engine's air-fuel ratio. The theoretically optimal air-fuel ratio is 14.7:1, and the ECU will maintain the air-fuel ratio near this theoretical optimum. The rear oxygen sensor also sends signals to the ECU, which compares the data from both sensors. If the data from both sensors is the same, it indicates that the three-way catalytic converter is faulty. The three-way catalytic converter can reduce pollutants in the exhaust gas, which is very important for environmental protection.

[LeHarmony]

As an ordinary person who drives frequently, I feel that the front and rear oxygen sensors are like the car's nose and eyes, monitoring exhaust emissions. The front oxygen sensor is located near the exhaust manifold and measures the oxygen level in the exhaust in real time, helping the engine computer adjust the fuel injection to achieve the ideal air-fuel ratio. This makes acceleration smoother and fuel consumption lower when driving, saving a lot of money. The rear oxygen sensor is positioned after the catalytic converter, checking whether the exhaust is clean and ensuring pollutants are treated. If it fails, the emissions light will come on, affecting the annual inspection. These two work together to ensure the car runs efficiently, being both environmentally friendly and reliable. In daily driving, their failure can lead to reduced power or a spike in fuel consumption, so it's best to check them every few tens of thousands of kilometers to avoid bigger problems.

[LucyLee]

The function of oxygen sensors is quite straightforward: the upstream oxygen sensor monitors oxygen levels in the exhaust system, allowing the ECU to optimize the air-fuel ratio and improve fuel efficiency; the downstream oxygen sensor verifies the performance of the catalytic converter, ensuring emissions compliance. From a technical perspective, they generate voltage signals in response to changes in oxygen concentration. If the upstream sensor fails, the engine may run too rich, leading to reduced power and increased pollution; if the downstream sensor malfunctions, the catalytic converter may become ineffective, resulting in excessive emissions. These sensors significantly impact overall vehicle performance, so regular maintenance to prevent carbon buildup is essential. Simply put, they work behind the scenes to maintain efficient and clean operation, and keeping them in good condition can extend the vehicle's lifespan.

[PhoebeFitz]

When it comes to oxygen sensors, during maintenance I found that the front oxygen sensor is primarily responsible for controlling fuel injection quantity, measuring the oxygen content in engine exhaust to ensure complete combustion; while the rear oxygen sensor checks the working efficiency of the catalytic converter. If the front sensor is damaged, the car will run poorly with increased fuel consumption; if the rear sensor fails, the emissions light stays on constantly, and even the catalytic converter may malfunction, leading to much higher repair costs. It's recommended that car owners perform regular diagnostic scans, clean carbon deposits, and have these sensors inspected every 60,000 kilometers. Though small, these sensors are crucial for safety and efficiency. Neglecting them could result in major repair expenses. Addressing minor issues promptly is the wise approach.