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.