Durable stainless steel oxygen sensor adapter - Made from high quality stainless steel for longevity and corrosion resistance - Provides excellent sealing, is waterproof, heat resistant, and high strength - Designed for a long service life in demanding exhaust environments Wide compatibility - Compatible with most vehicles that have an M18 x 1.5 oxygen sensor bore - Many modern vehicles use an M18 x 1.5 thread spacing for the O2 sensor Easy installation - Very simple to install: remove the oxygen sensor, screw in the adapter, then reinstall the sensor Practical use with high performance catalysts - If you install a high performance catalyst, increased airflow can trigger the engine warning light - The oxygen sensor adapter separates the rear oxygen sensor from the exhaust, allowing the vehicle ECU to assume the original catalyst is still present Use scenarios - Upgrading to a high-flow catalyst or performance exhaust on a vehicle with a rear O2 sensor, to prevent MIL while maintaining system appearance to the ECU - When installing aftermarket catalysts, to preserve ECU behavior and avoid erroneous sensor readings - General use on vehicles with M18 x 1.5 sensor bores for easy retrofit and compatibility with modern O2 sensor setups