Integrated Engineering Cat Back Exhaust System Audi S4 B9/B9.5 3.0T

The IE Catback Exhaust System for your Audi B9/B9.5 S4 incorporates our in-house engineered DroneTrap technology to deliver a truly aggressive exhaust note without any annoying drone or rasp. Engineered with cutting-edge design features, including mandrel-bent stainless steel, TIG welding, multi-point reinforcements, and oversized quad tips. Experience the elevated and enriched sound your S4 deserves.

IE's advanced DroneTrap technology captures the pulse waves responsible for your B9 3.0T engine's exhaust note and draws them into dual mathematically tuned resonators. The internal ports are engineered to resonate these waves against each other in a process that selectively cancels out those responsible for annoying drones. The remaining waves produce the deepened and enriched exhaust acoustics you love.

What is the point of a larger exhaust that looks stock? Stand out from the crowd with oversized 90mm quad slash-cut exhaust tips. These aggressive-looking tips fill the factory exhaust cutouts for that high-end sporty look.

Our catback design includes all sections to replace the factory exhaust tips, mufflers, and resonator up to the midpipes. Enjoy an unrestricted system that delivers the perfect exhaust note from your turbocharged V6 engine.

Advanced 3D scanning tools and cutting-edge software provide our engineers with a high-resolution digital model of the Audi B9 S4 chassis. This data is then used to maximize the exhaust size for flow and optimize all available space for the perfect catback fitment.

All piping is constructed of mandrel-bent T304L stainless steel to offer superior corrosion resistance. All joints are hand TIG welded using precise fixtures and tooling. We take great pride in knowing your new exhaust will sound remarkable and stand the test of time.

All piping is constructed of mandrel-bent T304L stainless steel to offer superior corrosion resistance. All joints are hand TIG welded using precise fixtures and tooling. We take great pride in knowing your new exhaust will sound remarkable and stand the test of time.

Engine movement and exhaust weight are transferred into the exhaust hangers, which puts a lot of stress on the mount brackets. IE's catback system is manufactured with multi-point and boxed-in hanger mounts designed to stand the test of time. Drive confidently knowing your exhaust is securely mounted and protected against annoying rattles or breaks.  

Sections comprised of dual 2.5" piping running in parallel are reinforced and bridged to offer superior strength and weight dispersion. This minor detail works hard to reduce stress on the welds and protect the piping from vibrations and twisting that can lead to leaks and rattles.

Enjoy a tuned and enjoyable exhaust note without any raspy leaks ruining the show. Our exhaust system assembles with our wide-width stretch clamps designed to seal and pull your exhaust connections together. This style of clamp design is popular in high-end OE applications and is known for long-term reliability.