3-bolt header flange/reducer connects to standard header flanges, Slip fit outlet for welding or clamping to your new or existing exhaust pipes, 2.5-inch diameter inlet/outlet flange made from T304 stainless steel, Includes 3-bolt flange gaskets and mounting hardware, Sold as a pair 3-Bolt Exhaust Flange Collector w/ O2 Bung, 2.5-inch SS Sku # 9302504 Mfr. Part # 9302504 Condition New Brand Speedway Motors Sold Pair Details
- Traditional 3-bolt header flange bolt pattern for 2.5-inch header collectors
- Outlet features slip fit/weldable connection to your existing or new exhaust tubing
- Manufactured from T304 stainless steel materials with a raw finish ready for coating
- Oxygen sensor bung welded into tube with O2 sensor plug included
- Sold as a pair and includes mounting hardware and 3-bolt flange gaskets
Add Oxygen Sensor Bungs to Your Exhaust with Standard 3-Bolt Header Flanges
Many headers today still use the standard 3-bolt header flange connection at the header collector. It is a simple and easy way to connect your exhaust system to your tubular headers. While some headers include a mating 3-bolt flange “starter tube” in their header kit, not all do. On top of that, older headers that were not designed around the use of aftermarket fuel injection systems, wideband oxygen sensor air/fuel gauges, and even the use of wideband O2 sensors as part of dyno tuning, do not have an easy way to install the O2 sensor without having to remove the header, drill a hole, and weld in an oxygen sensor bung. If you need to add an O2 sensor bung to your header our 3-bolt header flange with integrated O2 sensor bung is what you need!
Made from T304 stainless steel, our 2-1/2-inch diameter 3-bolt exhaust flange features a matching 2-1/2-inch outlet connection ready to weld or Shop Exhaust Band and Tube Clamps to your exhaust or turbo system hot side. The oxygen sensor bung comes pre-installed, saving you time and frustration. The oxygen sensor bung can be used for your Shop Retrofit EFI Systems wideband oxygen sensor, or the sensor that is included in an Shop AFR Gauges. As mentioned above, many dyno tuners run a wideband oxygen sensor for dyno tuning as well, so having the O2 sensor bung ready at hand makes things easy. An O2 sensor plug is included for each O2 sensor bung when the bung is not in use or not required, so there’s no need to screw in an old spark plug! Just thread in the included oxygen sensor plug. See our full line of Shop Speedway Motors Header Flange Reducers if you’re looking for additional inlet/outlet sizes.
Specs Overall Length 4.10" Centerline of Holes 3.54" Flange Thickness .250" Gasket(s) Included Yes Hardware Included Yes Material Type 304 Stainless Steel Finish Raw Sold in Quantity Pair Flange Style 3-Bolt Oxygen Sensor Bung Included Yes Reviews I would buy this product again Rated by Sevillfleetwood on July 18, 2026
Summary: thanks
Yes, I recommend this product.
Related Items / Suggested Parts QA1 9072-105 Anti Seize Anti-Seize Lubricant, 1 oz Oxygen Sensor, Sniper EFI or Terminator X Series & Tool Replacement NTK Wideband Oxygen Sensor & Tool Powerbuilt 648442 Oxygen O2 Sensor Socket, 1/2 In, Dr, 7/8 / 22mm Innovate Motorsports 37370 Bosch LSU 4.2 5-Wire, O2 Sensor Oxygen Sensor Weld-On Bung and Plug Kit, M18-1.5, Stainless Steel FiTech 60012 O2 Oxygen Sensor Bung Kit Tech Support We\'re here to help before and after your purchase. If you have a question or need assistance with one of our products, please contact us through Messaging and a knowledgeable Speedway Motors team member will be happy to help. About Speedway Motors is America’s Oldest Speed Shop® and has been a trusted source for specialty rodding and racing products and friendly expert advice for more than 74 years. Founded in 1952 by “Speedy” Bill Smith – a racer and street rodder himself – Speedway has grown from a one-man operation to become the world’s largest manufacturer, distributor and retailer of street rod and racing products. Our industry-leading fast delivery is the result of same-day shipping from our state-of-the-art, centrally located 500,000 sq. ft. headquarters. Speedway’s size offers customers unmatched product selection and low pricing, while our excellent technical support and customer service have made us a recognized leader in the rodding and racing industries.
