3in To 2-1/2in Collector W/O2 Sensor Bung B&S

The 3in To 2-1/2in Collector W/O2 Sensor Bung B&S from Hedman is a precision exhaust reducer engineered for custom exhaust systems where header-to-pipe diameter transitions are critical. As a mechanic working with performance and street-driven builds, you'll recognize this collector as essential when stepping down from a 3-inch primary diameter to a 2.5-inch downstream piping—a common scenario in engine swaps, turbo upgrades, or mid-range engine modifications where flow continuity matters. This reducer handles the aerodynamic transition smoothly, minimizing turbulence and backpressure while maintaining structural integrity under thermal cycling.

Constructed from steel with a durable black paint finish, the 3in To 2-1/2in Collector W/O2 Sensor Bung B&S features a 3-bolt ball and socket flange connection—the industry standard for vibration absorption and misalignment tolerance in exhaust work. The integrated oxygen sensor bung allows direct O2 sensor installation without drilling or welding, preserving emissions monitoring capability in street-legal applications. Hedman's engineering ensures proper flow characteristics through the reducer diameter, and the included hardware simplifies installation. Weighing 1.99 lbs with compact dimensions (5.8 x 4.25 x 6.9 inches), this piece integrates into tight engine bay configurations without compromise.

This collector reducer suits custom fabricators, performance shops, and DIY enthusiasts building or upgrading exhaust systems on V8 swaps, turbocharged applications, or street/strip vehicles requiring emissions compliance. The ball and socket design accommodates minor header-to-pipe misalignment, reducing installation stress and extending component life. Verify that your downstream piping accepts 2.5-inch OD tubing and confirm header outlet diameter is 3 inches before purchase. Installation requires standard exhaust gaskets and hardware—the package includes fasteners, but quality high-temperature gaskets should be sourced separately for reliability.