Borla 04-07 STi XR-1 Cat-Back Exhaust

This Borla cat-back exhaust system is built for the verified 2004-2007 Subaru Impreza WRX STI application listed below. Select it by exact manufacturer part number 140075 and confirm the full engine, drivetrain, body, wheelbase, factory-exhaust, and Borla application notes before ordering.

Key Features

• 3″ Tubing Diameter: Maximizes exhaust flow from the catalytic converter back, unlocking power and supporting turbo tuning potential.
• 4.5″ Polished Single Left Rear Tips: Angle-cut, rolled-edge T-304 stainless steel tips add aggressive styling visible from behind.
• XR-1 Multi-Core Muffler Technology: Patented straight-through design reduces backpressure for gains in horsepower, torque, and fuel mileage.
• Ships as complete bolt-on kit; no cutting or welding required for stock applications.
• Bolt-on design uses factory hangers and mounts; 1-2 hours typical install time.
• Uses only T-304 austenitic stainless steel for strength beyond aluminized or 409 materials.

Fitment

Specifications

What’s Included

One new Borla product identified by manufacturer part number 140075. Clamps, hangers, gaskets, tips, pipes, tools, and companion parts are included only when expressly listed for this exact part number.

About Borla

Borla develops stainless-steel exhaust systems, mufflers, tips, pipes, and related components for vehicle-specific and universal performance applications. Product selection remains exact-application and exact-part-number specific.

Related Borla Products

• Borla 03-09 Mazda RX-8 1.3L Single Round Rolled Angle-Cut Cat-Back Exhaust
• Borla 07-21 Toyota Tundra 4.6L/5.7L Cat-Back Touring SS Catback Exhaust w/ Black Chrome Tips
• Borla 13-15 Hyundai Veloster Turbo 1.6L AT/MT FWD 2dr Dual Center Rear Exit Cat-Back Exhaust

Browse the Borla collection for related exhaust systems and components.

Frequently Asked Questions

Will this Borla part fit my 2004-2007 Subaru Impreza WRX STI?
That application is listed, but confirm the engine, drivetrain, body or cab style, wheelbase, factory exhaust layout, tip opening, and every Borla application note before ordering.

Will this change require an engine tune?
A cat-back, axle-back, tip, muffler, or post-catalyst component usually does not require tuning, but confirm the exact application, emissions configuration, oxygen-sensor locations, and local requirements before installation.

What should I inspect before installation?
Check the shipping carton and components against the exact part number, then inspect clamps, hangers, gaskets, mating flanges, clearances, tip alignment, and required reused factory hardware before removing the original exhaust.

Installation Instructions

Follow the current Borla instructions and vehicle service information for this exact part number. Let the exhaust cool, support the vehicle safely, compare all parts before removal, protect sensors and wiring, use the specified clamps and torque values, align all joints and tips without preload, confirm body and suspension clearance, check for leaks, and retorque after the first heat cycles. Professional installation is recommended.