Kooks 3" SS H.O. GREEN Catted ULTRA X-Pipe. 06–13 Corvette C6 Z06/ZR1. Connects to OEM — 21613421

3" Stainless High Output GREEN Catted ULTRA X-Pipe

Unleash the full potential of your 2006–2013 Corvette C6 Z06 or ZR1 with a Kooks H.O. GREEN Catted ULTRA X-Pipe engineered exclusively for LS7 and LS9 performance. Designed to integrate with 3" OEM-style exhaust systems, this upgraded ULTRA X configuration uses a full-length Long Merge to improve scavenging, enhance overall exhaust efficiency, and deliver the unmistakable X/H-inspired tone Corvette enthusiasts love.

Equipped with H.O. GREEN catalytic converters, this system refines exhaust character while preserving the aggressive personality expected from a ULTRA X layout. Expect a crisp, exotic edge under acceleration complemented by a deeper, more composed mid-range resonance, providing a balanced, performance-driven sound that stands out without overwhelming rasp.

Crafted from premium 3" stainless steel and built for high-performance applications, this system pairs only with Kooks Long Tube Headers. Together, they create a smooth, unrestricted exhaust path that sharpens throttle response and elevates the driving experience of your LS-powered Corvette.

Features & Benefits

• H.O. GREEN Catted ULTRA X design for improved performance and refined exhaust tone

• Full-length Long Merge for enhanced exhaust pulse scavenging

• Includes front connections to interface directly with Kooks Long Tube Headers

• High Output High-flow catalytic converters for smoother, more controlled sound output

• Mandrel-bent 3" stainless steel tubing for optimized flow and long-term durability

• CNC-built construction ensures precision fitment and consistent quality

• Connects directly to 3" OEM (Z06/ZR1-style) rear exhaust systems

Fitment Notes

• Designed for 2006–2013 Corvette C6 Z06/ZR1 (LS7/LS9)

• Requires Kooks Long Tube Headers

• Connects to 3" OEM (Z06/ZR1-Style) exhaust systems

• H.O. GREEN Cats support up to 1,000+ RWHP

Part number: 21613421

Vehicle application

2006-2013 Chevrolet Corvette Z06 7.0L V8, 2009-2013 Chevrolet Corvette ZR1 6.2L V8

Emissions requirements vary by application. Verify the manufacturer’s product-specific requirements before ordering.

WARNING: This product can expose you to chemicals including Chromium and Nickel, which are known to the State of California to cause cancer, birth defects or reproductive harm. For more information go to www.p65warnings.ca.gov

Professional installation available at League Motorsports — Los Angeles.

Financing available — Apply here.

Not sure what your fitment is? Contact us by phone at 213-372-5955, DM us on Instagram, or email info@leaguemotorsports.com.