APR 18-25 Audi S4/S5 (B9) Catback Exhaust System

Designed for enthusiasts seeking the perfect balance of power, sound, style, and quality, the APR Catback Exhaust System for the Audi B9 S4 and S5 is a testament to engineering excellence. With its performance-driven design and durable construction, this system not only transforms your driving experience but also ensures years of reliable performance.

• Complete catalyst-back system including downpipes, extending from the factory catalyst back.
• Performance gains of 10 HP and 12 FT-LBS of torque delivered to all four wheels.
• 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.
• 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.
• Includes an upgraded tunnel brace to accommodate the larger piping.
• Integrated Helmholtz resonator minimizes drone and enhances sound quality.
• Valve-controlled rear mufflers dynamically adjust sound based on driving style.
• Removable quad 3.5” motorsport-style polished tips with APR logo; optional styles available.
• Smooth transitions and straight-through components maximize performance by reducing restrictions.
• Strikes the perfect balance of power, sound, style, and quality for enthusiasts.
• Fully emissions compliant for worry-free operation.

Vehicle Fitment: Fits Audi S4 18-25, S5 18-25

This part also goes by the following cross reference.

Cross Reference Part Number: aprCBK0012