Car Cel Fix Check Engine Light Eliminator Oxygen O2 Sensor Adapter M18x1.5Explain: 1. Made of highquality materials, durable and practical. 2. Don't expand only when the extension doesn't work. This is the builtin real Mini catalyst. 3. When the catalyst is removed, the rear oxygen sensor will display higher temperature and higher flow of unburned fuel. 4. As a result, this throws a check engine light (unit, SES, DTC) with error codes typically p0420 (catalyst system efficiency below threshold library 1) and or p0430 p0420 catalyst system efficiency below threshold library 2). Off road only . Specifications: Size: about 46.5x16mm Size: external thread M18*1.5 internal thread M18*1.5 length 46.5mm Material: Stainless steel Package list: Oxygen O2 Sensor*1