Mild Steel Oxygen Sensor Bung and Stainless Steel Plug Kit. (1) Mild Steel O2 Sensor Bung (18mm-1.5 thread). Our Mild Steel Bung and Stainless Steel Plug kit is perfect for adding a wide band to a turbo kit or performance exhaust system, features the standard 18mm-1.5 threaded hole for the most common 02 sensors.
