Kooks 2024 Mustang GT/D.H. 5.0L 4V 2in x 3in SS Headers w/ H.O Green Catted Connection Pipe

Race-Engineered 2 Inch Long Tube Headers for the 2024 Ford Mustang GT and Dark Horse 5.0L Coyote

The Kooks 21502400 is a 2 inch by 3 inch long tube header and H.O. GREEN catted connection pipe system developed specifically for the S650 Mustang GT and Dark Horse with the 5.0L Coyote 4V, delivering the maximum primary tube diameter available to unlock the full potential of Ford's most capable naturally aspirated Mustang platform.

Oversized 2 inch mandrel-bent T304 stainless primaries flow into 3 inch merged collectors carrying Kooks' patented scavenging spikes, which accelerate exhaust gas through the collector transition and reduce back pressure that factory manifolds produce throughout the entire RPM range.

The included H.O. GREEN catted connection pipes use high-output 300 CPSI catalytic converters rated for forced induction applications up to 750 rear-wheel horsepower, enabling the 21502400 to remain 49-state EPA compliant while dramatically improving exhaust flow for both naturally aspirated and power-adder builds. Dual bolt pattern header flanges allow the 21502400 to adapt to both OEM and aftermarket catback systems without modification. A professional ECU tune is required after installation to properly calibrate the S650 engine management system for the improved exhaust flow.

Kooks engineers purpose-built the 21502400 for the 2024 S650 Mustang GT and Dark Horse chassis, using 3/8 inch laser-cut flanges with hand-ported cylinder head inlets that match the Coyote 4V port geometry precisely. Every component is TIG-welded from 16-gauge T304 aircraft-quality stainless steel and built to order in Kooks' USA facility. The complete kit includes all gaskets, O2 sensor extension harnesses, clamps, and Stage 8 locking bolt hardware. California residents: this product does not meet CARB standards and is not legal for street use in California.

Key Features

• 2 Inch Primary Tubes: Maximum primary diameter for the Coyote 5.0L, maximizing top-end power on naturally aspirated and power-adder builds.
• H.O. GREEN Catted Connection Pipes: 300 CPSI high-output catalysts rated to 750 RWHP, EPA-verified for 49-state street use.
• Kooks Patented Scavenging Spike Collectors: 3 inch merged collectors with patented inserts reduce turbulence and accelerate exhaust gases for continuous scavenging.
• Dual Bolt Pattern Header Flanges: Compatible with OEM and most aftermarket catback systems without adapters or modifications.
• 3/8 Inch Laser-Cut Flanges: Hand-ported to match Coyote 4V port dimensions, eliminating gasket blowout and exhaust leaks.
• T304 Aircraft-Quality Stainless Steel: 16-gauge mandrel-bent tubing with full TIG welds for long-term durability.
• Tune Required: ECU recalibration is required after installation for correct air/fuel ratios and peak power output.
• Made in the USA: Built to order at Kooks' American facility.

What's Included

• Left and right 2 inch x 3 inch T304 stainless steel long tube headers with scavenging spike collectors
• Pair of H.O. GREEN 3 inch x OEM catted connection pipes with 300 CPSI high-output catalysts
• OEM-style exhaust adapters
• Stage 8 locking header bolts and mounting hardware
• Exhaust port gaskets
• O2 sensor extension harnesses
• Clamps
• Installation instructions

Product Specifications

This Part Fits

Frequently Asked Questions

Does the Kooks 21502400 require a tune on the 2024 S650 Mustang?
Yes. A professional ECU tune is required after installing the 21502400 to optimize air/fuel ratios and prevent check engine lights. The S650 Mustang's engine management system requires recalibration to take full advantage of the improved exhaust flow.

Will the Kooks 21502400 trigger a check engine light?
Without a tune, likely yes. After a proper tune utilizing the included H.O. GREEN catalysts, most builds operate without triggering CEL codes. Results depend on the tune, ECU calibration version, and supporting modifications.

How does the Kooks 21502400 compare to the 1-7/8 inch version for the S650?
The 21502400 uses 2 inch primaries for maximum top-end flow, making it the better choice for builds targeting high horsepower with forced induction or aggressive camshaft upgrades. For a primarily street-driven S650, the 1-7/8 inch version delivers a wider powerband, while the 2 inch version is optimized for peak output.

Does the Kooks 21502400 work with factory Ford Performance upgrades?
The dual bolt pattern header flanges on the 21502400 provide broad compatibility with OEM and aftermarket catback systems. Consult a professional tuner for compatibility with specific Ford Performance packages.

Is the Kooks 21502400 legal in California?
No. The 21502400 does not meet CARB standards and is not legal for street use in California or other CARB-regulated states. It is 49-state EPA compliant outside California.

How long is the lead time for the Kooks 21502400?
The 21502400 is built to order in the USA. Lead time is typically 4 to 6 weeks from the order date.

What does the H.O. GREEN designation mean on the connection pipes?
H.O. GREEN refers to Kooks' High Output GREEN catalyst specification, featuring 300 CPSI high-flow metallic substrate converters engineered for forced induction applications up to 750 RWHP. They are EPA-verified for 49-state street legal use.

Does the Kooks 21502400 fit the 2024 Mustang Dark Horse with the Handling Package?
Yes. The 21502400 fits all 2024 Mustang GT and Dark Horse trims including those equipped with the Handling Package, as the exhaust manifold mounting points are identical across all S650 variants with the 5.0L engine.

What is the warranty on the Kooks 21502400?
Kooks provides a limited lifetime warranty on all stainless steel header components and a 25,000-mile warranty on the H.O. GREEN catalytic converters in the connection pipes.

Prop 65 Warning

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 other reproductive harm. For more information, visit www.p65warnings.ca.gov.

Installation Instructions

Safely lift and support the S650 Mustang GT or Dark Horse on a lift or jack stands. Remove the factory exhaust manifolds after disconnecting oxygen sensor connectors and coolant lines if applicable. Clean the cylinder head flanges and install the Kooks 21502400 headers using the included port gaskets and Stage 8 locking bolts, torquing to spec in the sequence shown in the included instruction sheet. Connect the H.O. GREEN connection pipes from the collectors to the factory catback or aftermarket catback using the included OEM adapters and clamps. Reconnect O2 sensors using the provided extension harnesses. A professional ECU tune is required after installation. Due to the tight clearances in the S650 engine bay, professional installation is strongly recommended. Set aside a full day for the install.