Also available: Core only, no cones (24501) | UHO+ Mid-Bed 3.000" (25031)
OEM-STYLE DUAL-BRICK DESIGN, WELD-READY WITH 3.000" CONES — G-SPORT GEN2 ADVANCED UHO MID-BED
The G-Sport Gen2 Advanced UHO Mid-Bed Catalytic Converter (24531) replicates the layout many OEM converters use — two separate catalyst bricks in a single housing with an oxygen sensor port between them — as a complete weld-in unit with 3.000" inlet/outlet transition cones already installed. Rated up to 850hp per converter (per exhaust bank), it drops into 3.000" systems without any cone fabrication.
WHAT IS A "MID-BED" CATALYTIC CONVERTER?
A Mid-Bed cat is a specific type of GEN2 catalytic converter that contains two separate catalyst bricks within a single housing, with an oxygen sensor port located between them — mirroring the design commonly found in many OEM catalytic converters. GESi developed the Mid-Bed option as a high-performance, emissions-compliant replacement that maintains the physical and functional characteristics of factory catalytic systems, with the durability and flow of the proven S-Wound core. The primary brick runs a 400 CPSI cell count with a 200 CPSI secondary, and the Gen2 coating supports the advanced OBD monitoring on 2017 and newer vehicles while remaining compatible with all model years.
FEATURES
- OEM-style dual-brick layout with mid-bed O2 sensor port — preserves factory emissions characteristics
- Weld-ready: 3.000" inlet/outlet transition cones installed — no cone fabrication required
- Rated up to 850hp per converter — 4.500" body (UHO tier)
- 400 CPSI primary / 200 CPSI secondary S-Wound metallic substrates with proprietary GEN2 wash coat
- Directional — the only directional converters in the G-Sport line; install in the flow direction marked on the body
- EPA compliant, 300 Series stainless steel throughout, spikes up to 1,600°F (not CARB certified; not for use on emissions-controlled vehicles in California)
SPECIFICATIONS
- Sold As: Complete converter with 3.000" transition cones installed
- Inlet/Outlet: 3.000"
- Body Diameter: 4.500" OD
- Overall Length: 10.000" (±0.125")
- Cell Count: 400 CPSI primary / 200 CPSI secondary
- O2 Sensor Port: mid-bed, between the two bricks
- HP Rating: up to 850hp per converter (per exhaust bank)
- Flow Direction: Directional — install as marked on the body
- Substrate: S-Wound metallic, furnace-brazed
- Material: 300 Series stainless steel
- EPA Compliant: Yes (not CARB certified)
- Weight: 5.25 lbs
- Connection: Welding Required
PERFORMANCE
In instrumented dyno testing with pressure probes upstream and downstream of the substrate, a properly sized G-Sport high-flow catalytic converter produced horsepower and torque curves identical to a straight pipe, with no measurable pressure drop across the core. Emissions reduction runs up to 99% for carbon monoxide, 98% for nitrogen oxides, and 95% for hydrocarbons.
APPLICATIONS & FITMENT
Choose the Mid-Bed when your build needs an OEM-style mid-bed O2 sensor location — emissions-sensitive applications, or replacements for factory dual-brick converters — at up to 850hp per bank in 3.000" tubing. Fabricating your own transitions? The core-only 24501 is the same unit without cones. Past 850hp, the UHO+ Mid-Bed (25031) is rated to 1,000hp. If your system does not need a mid-bed sensor port, the standard Gen2 UHO 3.000" (85230) packages 3.000" shorter.
For the full selection guide, see Understanding the G-Sport Catalytic Converter Lineup and our G-Sport FAQ.
INSTALLATION NOTES
Mid-Bed converters are directional — install in the flow direction marked on the body. Reversed flow will cause emissions failure and inaccurate O2 readings. This is a weld-in unit for 3.000" exhaust tubing; place it as close to the OEM converter location as practical — within 8"–24" of the turbo outlet or header collector on custom systems — and position the mid-bed O2 sensor in the supplied port. In dual-bank systems, run the same converter model on both banks. Full best practices, common mistakes, and a pre-flight checklist are in our G-Sport Installation Guidelines.
Not sure which generation or output tier your build needs? Email us at support@aceraceparts.com with your platform, power goal, and tubing size and we will point you to the right part.