Do not risk using extensions as they often do not function properly. This is a built-in mini catalytic converter emulator. The O2 sensor emulator works with the rear oxygen sensor to prevent the ECU from detecting the absence of a catalytic converter. When a catalytic converter is removed, the downstream O2 sensor may detect increased exhaust temperatures and higher levels of unburned fuel, which can trigger the check engine light (CEL), typically with diagnostic trouble 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 use on vehicles operated on public roads. Note that CEL illumination can also be caused by other issues, such as a faulty or overly sensitive O2 sensor. In some cases, the check engine light may remain on even after installing this emulator, potentially leading to additional error codes. This emulator is designed to address the most common P0420 code related to catalytic converter efficiency but may not resolve all CEL-related issues. Features: 1. Precision-machined threads for accurate fitment and consistent performance. 2. Simple design constructed from durable materials resistant to deformation and corrosion. 3. Universal fit for most vehicles with 18mm x 1.5 threaded oxygen sensor ports. 4. Made from high-quality metal for strength and long-term durability. 5. Easy installation—direct bolt-on design with no modifications required. Condition: New Type: O2 Sensor Simulator Adapter Thread Size: 18mm x 1.5 Material: Metal Color: Silver Package Contents: 2 x Oxygen Sensor Simulator Adapters Note: The package includes only the items listed above. Other accessories shown in images are not included. Lighting and display settings may cause slight variations in the color of the product as shown. Measurement may vary by +/- 1-3 cm.