Bosch Switching-Type Oxygen (O2) sensors provide precise air-fuel-ratio measurements to the ECU, ensuring stable combustion control and helping reduce emissions across a wide range of operating conditions. Evolving from the original thimble sensor Bosch pioneered in 1976, Bosch later developed planar narrowband designs that offer faster light-off, improved lambda accuracy, and quicker closed-loop operation. Using advanced ceramic elements, optimized heater control, and high-temperature-resistant materials, Bosch Oxygen (O2) sensors deliver consistent performance even under harsh thermal and vibration loads. Backed by more than five decades of OE development, Bosch supplies a full line of durable, accurate Oxygen (O2) sensors to the aftermarket with the same OE-proven quality trusted by vehicle manufacturers.

Bosch Wideband A/F Oxygen (O2) sensors provide continuous, high-precision measurements of the air-fuel ratio across the full lambda range, giving the ECU far more detailed information than traditional switching sensors. This enables exceptionally accurate air-fuel mixture control — supporting improved fuel efficiency, engine performance, and reduced emissions under all operating conditions. Bosch pioneered the first Wideband A/F Oxygen (O2) sensor, introducing the planar pump-cell design that has become the global standard for modern engine management and low-emission technologies. With fast light-off, optimized heater control, and robust ceramic construction, Bosch Wideband A/F Oxygen (O2) sensors deliver reliable performance even during rapid load changes and harsh thermal cycles. Backed by more than five decades of OE development, Bosch supplies a full line of durable, accurate Oxygen (O2) sensors to the aftermarket with the same OE-proven quality trusted by vehicle manufacturers.

Bosch SmartLink™ Universal Oxygen (O2) sensors combine OE-specification base sensors with a flexible, patented Posi-Lock® connector system designed for fast, reliable installation across a wide range of vehicles. Each sensor uses the same high-quality zirconia ceramic element and heater design found in Bosch OE applications, ensuring accurate air-fuel-ratio feedback and dependable performance. The SmartLink™ system features Posi-Lock® connectors that create secure, high-temperature & weather resistant electrical connections without the need for soldering, crimping, or specialty tools — allowing technicians to adapt the sensor to existing harnesses quickly and confidently. The extended lead length provides added flexibility for vehicles with damaged or shortened wiring, and the connector system can be reopened and reused if adjustments are needed. Engineered to provide an easy, universal installation experience, Bosch SmartLink™ Universal Oxygen (O2) sensors deliver professional-grade fit and function with the same OE-proven quality and dependability trusted by vehicle manufacturers.

Standard narrow band type Oxygen Sensors operate between 0 and 1 volts, and are only capable of accurately measuring a stoichiometric air/fuel ratio (e.g. 14.7:1). A richer or leaner condition results in an abrupt voltage change and is only useful for qualitative determination.

The Lambda sensor consists of two cells. It is made up of a Nernst type potentiometric oxygen concentration cell and an amperometric oxygen pump cell.