Genuine Bosch 17025 LSU 4.9 Wideband Oxygen Sensor – Delivers high-precision air/fuel ratio readings critical for engine tuning, emissions control, and performance calibration in a wide range of applications. Trusted Sensor for Wideband Controllers & Tuning Devices – Compatible with popular wideband systems including AEM, Innovate, Holley Terminator X and Sniper EFI, and more, making it a go-to choice for tuners and shops. Advanced LSU 4.9 Sensor Design for Faster Response & Longevity – Built with Bosch’s latest wideband technology, the LSU 4.9 offers enhanced accuracy, stability, and long service life, even under high-heat, high-load conditions. 38" Length Ideal for EFI, Dyno Calibration & Performance Builds – Whether you're dialing in AFR on the dyno or logging data on the street, this sensor ensures precise AFR control for optimal combustion and power. The Bosch 17025 LSU 4.9 Wideband Oxygen Sensor is a high-accuracy, fast-response O2 sensor designed for use with wideband controllers and engine management systems. As the industry standard for professional tuners, the LSU 4.9 sensor delivers consistent and reliable AFR readings, making it an essential tool for tuning and EFI calibration This sensor is built using Bosch’s proprietary wideband technology, offering faster light-off times, long-term durability, and superior resistance to fuel and exhaust contaminants. Its 5-wire configuration allows for real-time oxygen level detection across a broad range of conditions, essential for turbocharged, supercharged, and naturally aspirated engines alike. Compatible with many of today’s most popular wideband systems, including AEM UEGO, Innovate LC-2/MTX-L, Holley EFI, and others, the Bosch 17025 provides the trusted performance and precision required for high-horsepower builds.