O2 Sensor Weld-In Bung M18 x 1.5 – Mild Steel or Stainless Steel
525055
The O2 Sensor Weld-In Bung provides a secure, threaded mounting point for oxygen sensors in custom exhaust systems. Available in mild steel or stainless steel, this weld-in fitting features the industry-standard M18 x 1.5 thread used by most factory and aftermarket oxygen sensors. Ideal for exhaust fabrication, engine swaps, EFI conversions, and performance builds, it allows precise sensor placement in headers, collectors, and exhaust tubing.
Designed for off-road buggies, rock crawlers, race cars, and street-driven vehicles, this O2 sensor bung is compatible with narrowband and wideband oxygen sensors using M18 x 1.5 threads. Choose mild steel for conventional steel exhaust fabrication or stainless steel for corrosion-resistant stainless exhaust systems. The threaded port can also be sealed with a compatible O2 sensor bung plug when a sensor is not installed.
Includes:
- (1) O2 Sensor Weld-In Bung – Mild Steel or Stainless Steel (Select Material)
Important: Select the material that matches your exhaust fabrication requirements. Oxygen sensors and M18 x 1.5 bung plugs are sold separately.
Specifications
| Product Type | Oxygen Sensor Weld-In Bung |
|---|---|
| Thread Size | M18 x 1.5 |
| Thread Type | Metric / Female |
| Material Options | Mild Steel / Stainless Steel |
| Installation Type | Weld-In |
| Mounting Location | Exhaust Tubing / Header / Collector |
| Sensor Compatibility | Compatible M18 x 1.5 Narrowband & Wideband Oxygen Sensors |
| Bung Plug Compatibility | M18 x 1.5 Threaded O2 Sensor Plugs |
| Exhaust Compatibility | Mild Steel or Stainless Steel Exhaust Systems / Material Dependent |
| Engine Compatibility | Universal / Sensor Thread Dependent |
| Primary Application | Custom Exhaust Fabrication, Oxygen Sensor Installation & EFI Tuning |
| Quantity | (1) Weld-In Bung |
Fitment
Universal weld-in oxygen sensor fitting for compatible exhaust systems requiring an M18 x 1.5 threaded sensor port.
Common Applications:
- GM LS & LT Engine Swap Exhaust Systems
- Custom Headers & Exhaust Collectors
- Aftermarket EFI & Engine Management Systems
- Wideband Air/Fuel Ratio Sensor Installations
- Rock Crawlers & Rock Bouncers
- Ultra4 & Off-Road Race Vehicles
- Street Cars, Trucks & Performance Builds
- Custom Exhaust Fabrication & Repair
Fitment & Installation Notes:
- Compatible with oxygen sensors using M18 x 1.5 male threads.
- Supports compatible narrowband and wideband oxygen sensors.
- Select mild steel or stainless steel based on exhaust tubing material and welding requirements.
- Sensor mounting position and angle must follow the oxygen sensor manufacturer's recommendations.
- Ensure sufficient clearance for the sensor body, wiring, and removal during service.
- Verify sensor tip clearance inside the exhaust tubing before welding.
- A compatible M18 x 1.5 bung plug can be installed when the sensor port is unused.
- Oxygen sensors and bung plugs are not included.
Builder Note: Plan oxygen sensor placement before final welding, especially on tightly packaged LS and LT engine swaps. Position the bung where the sensor can sample exhaust flow accurately while remaining accessible for service. Keep the sensor and wiring away from excessive heat, chassis interference, and potential trail damage.
FAQ
What size oxygen sensor fits this O2 sensor bung?
This weld-in bung uses M18 x 1.5 female threads, making it compatible with most factory and aftermarket oxygen sensors using the standard M18 x 1.5 male thread.
Will this O2 sensor bung work with GM LS and LT engines?
Yes. It can be used in custom LS and LT exhaust systems equipped with compatible M18 x 1.5 oxygen sensors. Verify the sensor specifications and required mounting location for your engine management system.
Can this bung be used with a wideband O2 sensor?
Yes. Many aftermarket wideband oxygen sensors use M18 x 1.5 threads. Confirm the sensor thread size and follow the manufacturer's installation guidelines for accurate air/fuel ratio readings.
Should I choose a mild steel or stainless steel O2 bung?
Mild steel is a practical choice for conventional steel exhaust tubing, while stainless steel provides greater corrosion resistance for stainless exhaust systems. Select the material based on the tubing and welding process being used.
Where should an O2 sensor bung be installed?
Oxygen sensor bungs are commonly installed in exhaust collectors or downstream exhaust tubing where the sensor can properly sample exhaust gases. The exact location depends on the engine management system, sensor type, exhaust temperature, and manufacturer's installation requirements.
Can I plug the O2 sensor bung when a sensor is not installed?
Yes. A compatible M18 x 1.5 threaded O2 sensor bung plug can be installed to seal the opening when an oxygen sensor is not being used. The plug is sold separately.
Does this O2 sensor bung include an oxygen sensor?
No. This product includes one weld-in O2 sensor bung in the selected material. Oxygen sensors, threaded plugs, and additional exhaust fabrication components are sold separately.
