What is an oxygen sensor in the exhaust system?

An oxygen sensor, also known as an O2 sensor or lambda sensor, is an electronic device that measures the proportion of oxygen in the exhaust gas of an internal combustion engine. It is used to monitor the engine's air-fuel ratio, which is the ratio of air to fuel in the engine's combustion chamber. The oxygen sensor provides feedback to the engine's electronic control unit (ECU) so that the ECU can adjust the fuel injection or ignition timing to maintain the desired air-fuel ratio.

The oxygen sensor is located in the exhaust manifold or exhaust pipe, where it is exposed to the exhaust gas. The sensor consists of a ceramic element coated with a thin layer of platinum or other metal. When the exhaust gas flows over the sensor, the oxygen molecules in the gas react with the metal coating, creating a voltage. The voltage signal is proportional to the amount of oxygen in the exhaust gas, so the ECU can use it to calculate the air-fuel ratio.

Oxygen sensors are an essential part of modern internal combustion engines. They help to reduce emissions and improve fuel economy by ensuring that the engine is running at the optimum air-fuel ratio.

Here are some additional details about oxygen sensors:

* Oxygen sensors are typically located near the catalytic converter in the exhaust system.

* The sensor is heated to a high temperature (around 300 degrees Celsius) to ensure a quick response time.

* The oxygen sensor signal is typically used by the ECU to control the fuel injection system.

* Oxygen sensors can also be used to monitor the catalytic converter's efficiency.

Overall, oxygen sensors play a vital role in the efficient operation of modern internal combustion engines.