Oxygen Sensor Weld-On Bung and Plug Kit, M18-1.5, Stainless Steel

• Stainless steel weld-in O2 sensor bung for use with most oxygen sensors
• Features standard metric M18-1.5 thread pitch
• Includes threaded O2 bung plug for when sensor is not being used
• Machined lip provides accurate centering and easier welding

Add a Weld-On Oxygen Sensor Bung to Your Exhaust for EFI or Tuning Needs

Retrofit EFI systems utilize a wideband oxygen sensor in their self-tuning operation. The O2 sensor monitors the exhaust system for unburnt oxygen levels, helping the EFI system to run at peak efficiency by adjusting the air/fuel ratio on the fly. Installing one of these systems requires the use of an O2 sensor bung (note it is NOT a 02 sensor bung; the first character is an O for oxygen). While many include a clamp on oxygen sensor bung apparatus with a gasket, they are far from perfect. The best alternative is a weld-in O2 sensor bung solution. Additionally, utilizing a pair of these exhaust bungs allows external sensors to be added for dyno runs with wideband readings or even for carbureted applications to be tuned on the dyno. In these cases, the included oxygen sensor plug can be installed in place of the temporary sensor when not in use, preventing any exhaust leaks or being forced to use an old spark plug due to the matching M18-1.5 threads. Both the O2 bung and O2 sensor plug are machined from solid stainless steel round bar and hex bar stock, respectively.

Welding the O2 bung takes minutes and can be accomplished on or off the vehicle depending on where in the exhaust system the bung is being installed. If you don’t own a welder any exhaust shop can install the bung for you as well. The machined lip of our O2 bung provides centering in the hole created, ensuring there is nothing blocking the O2 sensor tip, while also providing a solid connection for welding. Optimize placement of the weld-in O2 sensor bung by ensuring the sensor will be above the midpoint of the exhaust tubing, towards the upper third of the pipe diameter with the sensor on an angle or straight up, and before any catalytic converter installed in the system. For vehicles with long tube headers the optimal placement is in the header collector or just after the collector flange. For cast manifolds or shorty headers optimal placement is right after the individual runners combine into the collector. Which side of the dual exhaust system will be dependent upon your EFI system’s wiring harness routing.