The Milltek Hi-Flow HJS Sports Cats (part number SSXCH111) with heat wrap are a high-performance upgrade for the C8 Corvette Stingray, E-Ray, and Z06. These large-bore catalysts feature HJS 200 CPSI cores for significantly improved exhaust flow compared to stock cats, allowing gases to exit more efficiently. The motorsport-grade F1-style heat wrap helps manage underhood temperatures, and the system delivers power and torque gains across the rev range — all without throwing a check engine light or requiring a tune.
Fitment Notes
Compatible with 2020+ C8 Corvette Stingray (6.2L LT2) and 2024+ C8 Corvette E-Ray (hybrid)
Uses OEM GM gaskets for installation.
Tuning / ECU remap not required — designed to run without CEL when used with stock headers, intake, and throttle bodies.
Included
Left-hand (LH) and right-hand (RH) cat assemblies (SSXCH111) with heat wrap for both sides
Motorsports-grade F1-style heat wrap pre-installed on the cats
Instructions / installation guide from Milltek
Product Specs
Catalytic Core: HJS 200 CPSI, Euro 6 HD spec
Material: 304L stainless steel
Weight Reduction: ~10 lb lighter than OEM catalysts per Milltek spec sheet.
Thermal Management: Wrapped in F1-style motorsport-grade heat wrap for better heat control.
Emission / Diagnostics: Designed to not trigger a CEL (check engine light) with factory ECU when installed with OEM components.
Performance Gains: Milltek lists “increased HP and TQ across the entire powerband.”
Construction Origin: Made in UK (Milltek Sport legacy engineering)
Product Features
High-Flow Catalyst Design – The 200 CPSI core boosts flow and reduces restrictions compared to stock cats, translating to real-world power gains.
Motorsport-Grade Heat Wrap – F1-style thermal wrap minimizes heat soak, protecting nearby components and helping maintain lower under-hood temperatures.
No Tune Required – Engineered to work with OEM headers and intake, without causing a CEL, making it a plug-and-play performance upgrade.
Significant Weight Reduction – By shedding nearly 10 lb compared to factory converters, these cats contribute to reduced weight and improved throttle response.
Durable Construction – Built from 304L stainless steel for long life and resistance to corrosion and thermal fatigue.
Professional Heritage – Made by Milltek in the UK, leveraging decades of motorsport and performance exhaust experience.
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