The O2 sensor fixture contains a miniature catalytic converter designed to help reduce exhaust emissions. It may assist in preventing the check engine light from illuminating due to catalytic converter efficiency issues, such as error codes P0420 or P0430, which are related to catalyst system performance. This device is engineered to simulate the presence of a functioning catalytic converter to the vehicle's ECU, particularly when the original converter has been removed. Removal of the catalytic converter can cause the downstream O2 sensor to detect changes in exhaust temperature and unburned fuel, potentially triggering diagnostic trouble codes. Note that check engine light alerts can also stem from O2 sensor malfunctions, which may generate additional error codes. This unit is not a repair for damaged sensors or emissions systems but may help in specific off-road applications where emissions controls are not required. Features: 1. Precision-threaded design for consistent fitment 2. Constructed from durable metal material, resistant to deformation and corrosion 3. Compatible with most vehicles using M18 x 1.5 O2 sensors 4. High-quality construction for long-term reliability 5. Simple installation with direct mounting Condition: New Type: O2 Sensor Spacer Thread: M18 x 1.5 Size: Approximately 1.85 x 0.98 x 1.18 inches Material: Metal Color: Silver Package Contents: 10 x Oxygen Sensor Spacer Note: The package includes only the items listed above. Other accessories are not included. Due to lighting and display differences, the actual color may vary slightly from the image. Measurement tolerance is +/- 1-3 cm.