APR 18-25 Audi S4/S5 (B9) Catback Exhaust System
The APR Catback Exhaust System for the Audi B9 S4 and S5 is a complete, high-performance exhaust solution that runs the entire length of the vehicle from the catalyst back. Inspired by the larger center-pipe design of the higher-output RS4 and RS5 models, this system is engineered to boost performance, elevate sound, and enhance aesthetics with customizable exhaust tips that are sure to make a statement. Crafted from premium materials and built with advanced manufacturing techniques, this system is designed to withstand harsh conditions and deliver lasting performance. Expect a bold, aggressive growl at wide-open throttle, along with an impressive gain of 10 horsepower and 12 FT-LBS of torque to all four wheels!
Features & Benefits
- Smooth transitions and straight-through components maximize performance by reducing restrictions.
- Removable quad 3.5” motorsport-style polished tips with APR logo; optional styles available.
- Complete catalyst-back system including downpipes, extending from the factory catalyst back.
- Mandrel-bent brushed piping paired with electropolished cast splitters for a refined finish.
- Precision brackets and slip clamps ensure accurate alignment and hassle-free installation.
- Premium T304 stainless steel construction with TIG welding for strength and durability.
- Optimized flow through dual 2.5” downpipes, 2.75” midpipes, and a 3.5” midpipe.
- Strikes the perfect balance of power, sound, style, and quality for enthusiasts.
- Performance gains of 10 HP and 12 FT-LBS of torque delivered to all four wheels.
- Valve-controlled rear mufflers dynamically adjust sound based on driving style.
- Integrated Helmholtz resonator minimizes drone and enhances sound quality.
- Includes an upgraded tunnel brace to accommodate the larger piping.
- Fully emissions compliant for worry-free operation.
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Excluded from Policy: Clearance, Closeout, Used, Refurbished or Open-box items.
Typical order handling and processing time is 24 hours for orders placed Monday through Friday. We do our best to ship orders immediately but we reserve the right to take up to four (business) days to ship in-stock products. Business days are Monday through Friday; orders are not guaranteed to be processed on weekends. Orders placed after 3pm EST will be processed the following business day, regardless of the shipping method. Additionally, UPS/FedEx delivers ALL orders Monday thru Friday, regardless of the shipping time. If you need an order to be delivered on a Saturday (this applies to Next Day Air orders only), there is a $20 Saturday delivery fee, and this can only be arranged for by calling in and placing your order over the phone.
For out of stock items, or special ordering please give us a call at (510) 359-7232
WARNING: May contain items that are found to have compounds and/or chemicals known to the State of California to cause cancer, birth defects, and reproductive harm. For more info, please visitP65Warnings.ca.gov
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