Bosch Wideband LSU 4.9 5 Wire O2 Sensor

The Bosch Wideband LSU 4.9 5-Wire O2 Sensor is a precision oxygen measurement device engineered for real-time engine fuel mixture monitoring in tuning and performance applications. This 5-wire wideband sensor from PROSPORT GAUGES provides the linear air-fuel ratio feedback that modern engine management systems and aftermarket tuning platforms require for accurate closed-loop control and diagnostic data logging.

The LSU 4.9 wideband design measures oxygen content across a wide lambda range, outputting a proportional signal that correlates directly to air-fuel ratio rather than the narrowband on/off switching of traditional O2 sensors. The 5-wire configuration includes signal, ground, heater power, heater ground, and reference voltage lines—a standard interface for Bosch wideband O2 sensors across automotive platforms. This design delivers faster response time and greater accuracy than single-wire or 4-wire alternatives, critical for tuners seeking precision fuel mapping during dyno work or street tuning. Dimensions of 4.05 × 2.15 × 6.05 inches and a weight of 0.39 lbs reflect a compact form factor suitable for tight exhaust manifold installations.

This sensor is essential for owners running wideband gauge displays, standalone ECUs, or tuning software that requires live lambda feedback. Whether monitoring a forced-induction engine, naturally aspirated build, or street performance vehicle, the Bosch LSU 4.9 5-wire O2 sensor (Bosch part number 17025) supplies the input data necessary for verifying and optimizing fuel delivery across the entire operating range. Users rely on wideband O2 measurement to prevent lean-condition damage during boost events, validate turbo or supercharger calibration, and confirm fuel system capacity under sustained high-load scenarios.