O2 sensor bungs M18 x 1.5 O2 Oxygen Sensor Weld In Bung & Plug M18 x 1.5 Stainless Steel Adapt O2 OXYGEN SENSOR M18 X 1.5 BUNG & PLUG WIDEBAND WELD ON IN NUT CAP Vibrant 45 deg Angled Oxygen Sensor Weld Bung (M18 x 1.5 Thread) Bulk OEM Factory Custom Auto Parts O2 Oxygen Sensor M18X1.5 Female Threaded. All Vibrant Performance exhaust bungs are made from the highest quality stainless and mild steel to ensure the utmost in quality for all professional aftermarket and O. E. M Exhaust projects.