BBK 1670 Extractor X-Chamber Mid-Pipe w/Cats for 1999-2004 Ford Mustang 4.6L

Vehicle Fitment

• 1999-2004 Ford Mustang GT (New Edge, 4.6L 2V SOHC V8, Coupe & Convertible)
• 2001 Ford Mustang Bullitt (New Edge, 4.6L 2V SOHC V8, Coupe)
• 2003-2004 Ford Mustang Mach 1 (New Edge, 4.6L 4V DOHC V8, Coupe)
• 1999-2004 Ford Mustang SVT Cobra (New Edge, 4.6L 4V DOHC V8, Coupe & Convertible)

Fitment Notes

• Designed for use with factory shorty exhaust manifolds or any aftermarket shorty headers - this X-pipe is NOT intended for use with long tube header applications.
• Factory O2 sensor bung locations are maintained - sensors plug in directly at the stock positions with no cutting, relocation, or extension required.
• 49-state legal - NOT approved for use in California or any state that has adopted California CARB emissions standards. Verify local emissions laws before purchasing.
• When pairing this BBK mid-pipe with a Flowmaster cat-back exhaust system, the driver-side lead pipe may not properly align due to manufacturing tolerances between brands. Professional modification may be required in this combination.
• Direct replacement for the factory mid-pipe - bolts directly to factory or aftermarket shorty headers and connects to the existing cat-back system with no cutting, welding, or fabrication under normal installation conditions.
• Sold as a complete X-pipe kit with catalytic converters included.

Features

• BBK proprietary die-stamped Xtracter center X-Chamber crossover design - the merged X section balances exhaust pulses between both cylinder banks, creating an extraction effect that pulls spent gases out of the engine more efficiently than a standard H-pipe or factory pipe design.
• Dyno-verified gains of 12-20 rear wheel horsepower and torque depending on the application - delivered through improved exhaust scavenging, reduced backpressure, and higher exhaust gas velocity across the RPM range.
• 2-1/2" (2.5") primary diameter tubing - significantly larger than the restrictive factory mid-pipe - providing increased exhaust flow capacity for both naturally aspirated and modified 4.6L builds.
• 16-gauge CNC mandrel-bent aluminized steel construction - maintains a consistent round tube cross-section through every bend, maximizing internal flow area and minimizing turbulence throughout the system.
• High-flow catalytic converters are pre-installed at the factory - improve exhaust flow over the restrictive OEM cats while retaining emissions equipment in the exhaust system.
• Factory-style die-stamped flanges at both the header connection and cat-back connection ensure a precision fit and long-term leak-free seal without the need for special gaskets or adapters.
• Aggressive V8 muscle car exhaust note - the X-chamber crossover adds a distinctive, crisp exhaust tone over the factory mid-pipe, delivering improved sound character alongside the power gains.
• BBK in-house dyno-tested at their own dynamometer facility - performance gains are validated before production, not based on theoretical estimates.
• Made in the USA - designed and manufactured domestically by BBK since 1988.

Specifications

• Part Number: 1670
• Product: Extractor Series X-Chamber Mid-Pipe with High-Flow Catalytic Converters
• Application: 1999-2004 Ford Mustang GT, Bullitt (2001), Mach 1 (2003-2004), SVT Cobra - 4.6L V8
• Pipe Style: Full-Length X-Pipe (Extractor X-Chamber crossover)
• Pipe Diameter: 2-1/2 inches (2.500 in.)
• Tubing Material: 16-gauge Aluminized Steel
• Tubing Fabrication: CNC Mandrel-Bent
• Crossover Design: BBK Proprietary Die-Stamped Xtracter X-Chamber
• Catalytic Converters: Yes - 2x High-Flow Catalytic Converters (pre-installed)
• O2 Sensor Bungs: Yes - Factory Location (plug-and-play)
• Flange Style: Die-Stamped (factory-fit header and cat-back connection)
• Header Compatibility: Factory Shorty Headers or Any Aftermarket Shorty Headers
• Estimated Power Gain: +12-20 rear wheel horsepower and torque (dyno-verified)
• Emissions: 49-State Legal - NOT CARB Approved (not legal in California)
• Package Weight: Approx. 24-34 lbs.
• Country of Origin: USA
• Warranty: 1-year manufacturer's warranty from date of purchase

Included Components

• 1x BBK Extractor X-Chamber Full-Length X-Pipe Assembly (2-1/2" aluminized steel, complete with crossover)
• 2x High-Flow Catalytic Converters (pre-installed on mid-pipe)

Product Description

The BBK 1670 Extractor Series X-Chamber Mid-Pipe is a direct-fit, full-length catted X-pipe engineered specifically for the 1999-2004 Ford Mustang equipped with the 4.6L V8 - covering the GT (2V), Bullitt, Mach 1, and SVT Cobra (4V) across both Coupe and Convertible body styles. At the core of the 1670's performance advantage is BBK's proprietary die-stamped Xtracter center X-Chamber crossover, which merges the exhaust streams from both cylinder banks at the mid-pipe's center point. This X-shaped merge creates a balanced scavenging effect that pulls exhaust gases out of the engine more efficiently than an H-pipe or the factory mid-pipe, resulting in dyno-verified gains of 12-20 rear wheel horsepower and torque depending on the application.

Construction uses 16-gauge, 2-1/2" CNC mandrel-bent aluminized steel tubing throughout - larger in diameter than the factory pipe - paired with factory-style die-stamped flanges that bolt directly to the OEM or aftermarket shorty exhaust headers at the front end and the cat-back system at the rear. Factory O2 sensor bung placement is preserved exactly, allowing the factory oxygen sensors to plug in directly without relocation, extensions, or modification. Two high-flow catalytic converters are pre-installed at the factory, improving exhaust flow over the restrictive OEM cats while keeping catalytic emissions equipment in the system for 49-state street use.

Important fitment notes: this X-pipe is designed for use with factory shorty manifolds or any aftermarket shorty headers - it is not suited for long tube header applications. When paired with a Flowmaster cat-back system, the driver-side lead pipe may require professional modification for proper alignment due to differences in manufacturing tolerances between the two brands. This product is 49-state legal but is not CARB approved and cannot be used in California or states following California emissions standards. Backed by BBK's 1-year manufacturer's warranty and made in the USA, the 1670 is one of the most popular and proven mid-pipe upgrades available for the New Edge 4.6L Mustang platform.