G-Sport Gen2 UHO+ EPA Compliant Catalytic Converter - 3.000" Inlet/Outlet - Mid-Bed Series (25031)

Also available: Core only, no cones (25001) | UHO Mid-Bed 3.000" (24531)

1,000HP 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 (25031) is the top Mid-Bed in the line: rated up to 1,000hp per converter (per exhaust bank), with two catalyst bricks in a single 5.000" OD housing, an oxygen sensor port between them, and 3.000" inlet/outlet transition cones already installed for direct weld-in installation.

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 1,000hp per converter — 5.000" body (UHO+ tier, Gen2 exclusive)
• 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: 5.000" OD
• Overall Length: 12.000" (±0.125")
• Cell Count: 400 CPSI primary / 200 CPSI secondary
• O2 Sensor Port: mid-bed, between the two bricks
• HP Rating: up to 1,000hp 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: 6.57 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 UHO+ Mid-Bed for builds between 850hp and 1,000hp per exhaust bank in 3.000" tubing that need an OEM-style mid-bed O2 sensor location. Fabricating your own transitions? The core-only 25001 is the same unit without cones. Under 850hp, the UHO Mid-Bed (24531) packages tighter. If your system does not need a mid-bed sensor port, the standard Gen2 UHO 3.000" (85230) runs 5.000" shorter overall.

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.