Wideband air fuel (AFR) oxygen (O2) sensor for precise air-fuel ratio measurement. Part numbers: 11787558055, 0258017098, 234 5139. Why you need it - Accurate AFR readings across the full operating range help your engine run as designed, improving control and response. - Provides reliable O2 data that supports proper fuel delivery and combustion efficiency. - Aids tuning, diagnostics, and performance improvements without guesswork. Key attributes - Function: wideband AFR measurement for engine management systems. - Compatibility: designed for use where a wideband O2 sensor is required; part numbers above identify the specific unit. - Performance: delivers precise O2 readings to help optimize combustion and fuel control. - Reliability: built to provide consistent data for engine tuning and monitoring. 2-3 practical use scenarios - Dyno tuning and ECU calibration: use the sensor to dial in the fuel map for optimal power and efficiency. - Performance upgrade projects: essential for engines with modifications (turbo, supercharger, exhaust) that need accurate AFR feedback. - Routine diagnostics and maintenance: monitor combustion efficiency and sensor health to sustain engine reliability. Note: This description preserves the original product focus, parts, and functions without altering the established specifications.