Features: This O2 sensor adapter includes a miniature catalytic converter designed to help prevent check engine light activation after exhaust modifications. It is intended for use when the catalytic converter has been removed or replaced with a high-flow unit. Unlike simple spacers or extensions, this device contains an actual mini catalytic converter to signal the ECU that the factory catalytic converter remains functional. When the catalytic converter is removed, the downstream oxygen sensor detects changes in exhaust gas composition and temperature, potentially triggering diagnostic trouble codes such as P0420 or P0430. For off-road use only. This is an oxygen sensor adapter only; other items shown in images are not included. Specifications: Material: Stainless steel Height: Approx. 4.65 cm (1.83 in) Thread size: M18 x 1.5 Color: As shown in product images Quantity: 1 piece Note: No retail packaging is included. Slight measurement variations (up to 1 cm) may occur due to manual measurement. Monitor settings may affect color representation. Package Contents: 1 x Oxygen sensor adapter