10 Pcs M18x1.5 For Lambda Sensor Oxygen Sensor O2 Oxygen Sensor Stainless Steel Iron Weld On Bung Plug Stepped Nut Cap Kit Nitrogen Oxide NOx Sensor

10 Pcs M18x1.5 For Lambda Sensor Oxygen Sensor O2 Oxygen Sensor Stainless Steel Iron Weld On Bung Plug Stepped Nut Cap Kit weld bungs with the STEP to drop right into the hole you drilled in your round tube for precise welding. Very shallow step for minimal to no protrusion into the pipe. The nitrogen oxide sensor is used to detect the nitrogen oxide content in the engine exhaust to optimize the exhaust. Helps the engine run efficiently with the air-fuel ratio.