The Kooks GREEN Catted X-Pipe is a high-performance exhaust crossover engineered to work in concert with Kooks long tube headers, delivering measurable gains in horsepower and torque across the full RPM range. The X-pipe crossover configuration promotes superior exhaust scavenging between cylinder banks — balancing flow, reducing backpressure, and unlocking power that a factory mid-pipe simply cannot match. Each unit is purpose-built for serious street, track, and high-output performance applications that demand both proven power and emissions-conscious construction.
What sets the GREEN series apart is Kooks' proprietary catalytic converter technology. GREEN cats — also known in the performance industry as GESI cats — are high-platinum, high-performance catalytic converters specifically engineered to maintain catalytic efficiency under the extreme exhaust gas temperatures generated by heavily modified and forced induction engines. These EPA-certified ultra-high-performance catalysts use a 400-cell high-flow substrate and are designed to handle what standard high-flow cats cannot, making them the correct choice for supercharged, turbocharged, and high-compression naturally aspirated builds running on pump gas or ethanol fuels.
Key Features:
- X-pipe crossover design for optimal exhaust scavenging and balanced flow between cylinder banks
- Kooks EPA-certified GESI ultra-high-performance GREEN catalytic converters — engineered for high-horsepower and forced induction applications
- 400-cell (CPSI) high-flow substrate for maximum exhaust throughput with emissions-compliant construction
- T304 aircraft-quality stainless steel construction throughout
- Precision CNC mandrel-bent tubing maintains consistent diameter for unrestricted exhaust flow
- TIG-welded construction for leak-free durability and long-term reliability
- Additional O2 bung included for air/fuel monitoring during tuning
- OEM-style outlet compatible with factory or aftermarket axle-back exhaust systems
- Dyno- and race-tested for maximum power output
- Backed by Kooks' limited lifetime warranty to the original purchaser
- Handcrafted in the USA by a three-generation, family-owned and operated company
Kooks Headers and Exhaust has been the leader in the high-performance exhaust industry since 1962, with hundreds of championships and records across NHRA, IHRA, NMCA, NMRA, NASCAR, NASA, SCCA, and many other sanctioning bodies. Every GREEN Catted X-Pipe is built to the same exacting standards that have made Kooks the trusted choice of serious performance enthusiasts for over 60 years.
NOTE: Requires Kooks long tube headers for proper installation. An ECU tune is recommended for optimal air/fuel ratio calibration after installation. Not legal for sale or use on emissions-inspected vehicles. Not CARB compliant — cannot be sold or used on California-registered vehicles.
WARNING: Cancer and Reproductive Harm — www.P65Warnings.ca.gov