G-Sport Gen2 UHO+ EPA Compliant Catalytic Converter Core - 5.000" Body x 7.000" Long - Mid-Bed Series (25001)

Also available: With 3.000" cones installed (25031) | UHO 4.500" Mid-Bed Core (24501)

1,000HP OEM-STYLE DUAL-BRICK DESIGN WITH A MID-BED O2 PORT — G-SPORT GEN2 ADVANCED UHO+ MID-BED CORE

The G-Sport Gen2 Advanced UHO+ Mid-Bed Catalytic Converter Core (25001) brings the OEM-style dual-brick layout to four-digit power: rated up to 1,000hp per core (per exhaust bank), with two catalyst bricks in a single 5.000" OD housing and an oxygen sensor port between them. This is the core-only version, ready for full custom integration.

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
• Rated up to 1,000hp per core — 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
• Nickel-lined, furnace-brazed substrates; 300 Series stainless steel throughout; spikes up to 1,600°F
• EPA compliant — third-party lab tested (not CARB certified; not for use on emissions-controlled vehicles in California)

SPECIFICATIONS

• Sold As: Catalytic core only (no transition cones)
• Body Diameter: 5.000" OD
• Overall Length: 7.000" (±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 core (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: 5.56 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 core for builds between 850hp and 1,000hp per exhaust bank that need an OEM-style mid-bed O2 sensor location. Prefer it weld-ready? The 25031 is this core with 3.000" transition cones installed. Under 850hp, the UHO Mid-Bed core (24501) packages tighter. If your system does not need a mid-bed sensor port, the standard Gen2 UHO+ core (85500) is 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. Weld in via custom transitions (or choose the 25031 with cones installed), place the unit 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.