The NOx (Nitrogen Oxide) Sensor is a high-temperature sensor designed to detect NOx levels in diesel-fueled vehicles that must comply with state emissions regulations. As state emissions requirements become more demanding for diesel vehicles, it is imperative to have a quality sensor to notify the driver when high amounts of NOx levels are in the engine. All Dorman products are engineered in the United States and backed by 100 years of automotive aftermarket experience. Our solutions are thoroughly tested and inspected, and if you experience any difficulty installing or using our parts, we have a dedicated technical support team of ASE Blue Seal certified professionals ready to help. To learn more about our quality and innovation, visit DormanProducts.com.