O2 Sensor weld-on bung – 303 Stainless Steel Thread: M18 x1.5

The Industry Standard for Wideband Installation

The O2 Sensor Weld-on Bung (303 Stainless Steel) is the definitive mounting solution for installing wideband oxygen sensors into stainless steel or mild steel exhaust systems. Accurate Air/Fuel Ratio (AFR) data begins with the sensor’s location and stability. This bung provides a rigid, leak-free port that withstands the extreme thermal cycling of a turbocharger downpipe or header collector.

Material Superiority

Crafted from 303 Stainless Steel, this bung offers superior machinability compared to standard 304, resulting in cleaner, sharper threads that resist galling—a common issue when installing and removing sensors frequently for dyno tuning. It is fully weldable to both stainless and mild steel exhaust tubing. The kit includes a high-quality copper crush washer and a screw-in blanking plug, allowing you to seal the port when the wideband sensor is not in use (e.g., after a tuning session).

Technical Specifications