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.
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 7 - Jul 12
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
IE Cat Back Exhaust Audi S4 B9 3.0TFSIThe 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. NO CHECK ENGINE LIGHT CEL FREE WITH STOCK
NO CHECK ENGINE LIGHT
CEL FREE
WITH STOCK DOWNPIPE
ENRICHED SOUND
DRONETRAP
WITHOUT DRONE
LARGE SLASH-CUT
QUAD TIPS
SPORTY DESIGN
LEADING FEATURES
- DroneTrap Technology -IE's proprietary no-drone resonator design
- Bolt-on direct fit -No cutting, no welding, no hassle
- Aggressive look -Large 90mm slash-cut quad tips
- High-flow design -Dual 2.5" piping to support any power output
- Reliable engineering -Leak free, stamped, & multi-point reinforced
- 50 states legal -No check engine light & emissions compliant
DESIGN DETAILS
STRONG, REINFORCED, RELIABLE
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.
QUAD SLASH-CUT TIPS
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.
COMPLETE BOLT-IN KIT
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.
OPTIONAL MIDPIPES
Want to take your catback to the next level? Add a set of IE Midpipes for an even larger boost in sound. By upgrading this section, you'll remove the two factory resonators and 12 feet of exhaust piping, further improving exhaust flow and acoustic notes.
Midpipe upgrade is optional, and the catback can be installed with either stock or IE midpipes.
ADVANCED ENGINEERING
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.
TIG WELDED T304L STAINLESS STEEL
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.
STAMPED RESONATOR
The DroneTrap system is wrapped up in our stamped multi-wall resonator that reinforces the housing inside and out. This high level of manufacturing protects the resonator from warping or splitting at the welds under exhaust movement.
REINFORCED HANGERS
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.
BRIDGED PIPING
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.
LEAK-FREE CLAMPS
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
HEAR IT IN ACTION
YOUR STERO SYSTEM IS OBSOLETE
3D model of IE catback, midpipes, and downpipe combined
DIAL IN YOUR EXHAUST
IE offers catback, downpipe, and midpipes upgrades to replace individual sections of your exhaust. Installing variations of these parts allows you to dial in your exhaust volume to your preference, from sporty to aggressive.
INSTALLATION
Install your IE catback without any permanent modifications or installation hassles. The installation process is straightforward and accomplished with standard mechanic tools. An auto-lift is highly recommended.
Install time around 3-4 hours
VEHICLE FITMENT GUIDE
| MAKE | MODEL | YEAR | ENGINE |
|
AUDI |
S4 |
2017-2020 |
3.0T (Turbocharged) |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.5 ★★★★★
Based on 2192 reviews
Sort
Product Reviews
★★★★★ 5
Our XL dogs love them. Highly recommend it!
Size: Mini, Color: Gator (Pink)
Our XL dogs love this! Highly recommend them! Highly recommend. Not for aggressive chewers but our big dogs don't destroy their toys. They cherish them. Great for play and cuddling. Not to loud either. Very cute.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 13, 2026
★★★★★ 5
When they said strong...
...they weren't kidding. Our pup would chew through everything she could get her sharks teeth into. Like my arms. Nothing lasted as long as a week or maybe two. But she has had Dino for months now. She loves him. He is the go to toy for when she wants to play tug. The material used to make this toy is every bit as strong as the seller claims. I will definitely buy from them again. And I will not wait for this one to rip. I may be waiting a long time. If your pup likes to tear stuff apart, feel safe in buying this toy,
UPDATE: 2/9/2023
Dino finally succumbed to the torture. His back ripped open and despite trying to repair him with ordinary thread he couldn't withstand the pressure, His stuffing was removed and spread all over the living room. Completely emptied he is still a good toy. Strong enough to withstand the forceful play of tug-o-war.
Only thing I would suggest is to use something stronger when closing his back. The rest of him is great. I will be replacing him soon.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 30, 2023
★★★★★ 4
Not so tough
Size: Mini, Color: Gator (Pink)
I bought this because I dog sit. The dog chews up every. Single. Toy. So I bought it since it was cheap and it can be in the “chunk” (the dog’s name) toy box. It is not durable at all. He tore it up just as fast as a cheaply made toy.
Chunk LOVES it! He would not stop playing with it. He loves the squeakers, it is a perfect size for him to throw it up in the air and chase it, and he loved ripping the legs off. It is good for my husband and I because there is little to no fluff.
However, it is the perfect size to drop behind the couch and not be able to get. So once he drops it behind the couch, he won’t get it until morning.
Now for my dog’s rating. My dog loves this toy too. He is much more gentle with toys (he has $5 Walmart toys we bought him back in 2020 in perfect condition that he plays with them every day). Before Chunk came over for the weekend, my dog Ted played with this. Ted is a larger small dog and chunk is a smaller small dog. And it is still the perfect size for both dogs.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 26, 2026
★★★★★ 5
Tough
Size: Large, Color: Dinos Frills (Pink)
Tough dog toy that's held up through multiple washes! My dogs love the squeaker. They are not destructive chewers so I can't really say how it would hold up with that kind of dog though.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 8, 2026
★★★★★ 5
Cute and well made my dogs love it.
Size: Mini, Color: Gator (Pink)
Cute little toy definatly for small toy sized dogs. This toy is bright and colorful and well made. My little dog likes it very much and tosses it around all the time. Great toy for fetch.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 5, 2026