Oxygen sensors, also known as O₂ sensors or lambda sensors, are used to measure the amount of oxygen present in the exhaust gases post-combustion. Typically located in the exhaust manifold or downstream of the catalytic converter, these sensors provide critical feedback to the engine control unit (ECU) for precise fuel mixture control. Most modern sensors utilize a zirconia ceramic element generating a voltage proportional to the oxygen content, while newer wideband sensors employ a more complex electrochemical process for faster and more accurate readings. Sensor types vary by vehicle application and emission standards, requiring specific connector and thread configurations. Accurate function is essential for maintaining optimal fuel efficiency, minimizing emissions, and preventing catalytic converter damage.