Do not risk using extensions as they typically do not function properly; this is a built-in real mini catalytic converter. This O2 check engine light (CEL) fixture with a miniature catalytic converter will make your ECU think the original catalytic converter is still installed. When the catalytic converter is removed, the rear O2 sensor detects higher temperatures and increased unburned fuel flow, which can trigger a check engine light (CEL), commonly with error codes P0420 (catalyst system efficiency below threshold bank 1) and/or P0430 (catalyst system efficiency below threshold bank 2). This device is intended for off-road use only and is not designed for long-term on-road use. In some cases, CEL alerts may be caused by O2 sensor issues, such as an overly sensitive sensor, which may still trigger the light even after installation. Additional error codes may still occur. Therefore, this CEL canceller (sometimes referred to as a mini cat) cannot resolve all check engine light issues. It is designed to address only the P0420 code related to catalytic converter efficiency (the most common issue). 1. Threads are precision-machined for accurate fitment and consistency. 2. Simple design with high-quality materials, resistant to deformation and rust. 3. Universal fit for most vehicles with 18mm x 1.5 O2 sensor bung size. 4. Constructed from high-strength, durable metal. 5. Easy installation with direct bolt-on design; no modifications required. Condition: New Type: O2 Sensor Gasket Adapter Thread: 18mm x 1.5 Material: Metal Color: Silver Package Contents: 2 x Oxygen Sensor Adapters Note: Light reflection and display settings may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1-3 cm. This product is intended for off-road use only and is not legal for use on public roads in all regions.