Integrated Engineering

IE ProCore Downpipe For Audi B9 S4 & S5

IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
IE ProCore Downpipe For Audi B9 S4 & S5
  • Description
  • Refund Policy

The IE ProCore Downpipe for your Audi B9 S4 or S5 delivers an improved exhaust note and increased flow. Our in-house engineered 6" 400CPSI catalytic converter channels substantial flow to support upgraded engine tunes and larger turbochargers. The specialty tri-core design and precious metal coatings align with ECU emissions requirements so that you can upgrade without the check engine light.



6" 400CPSI





  • IE ProCore catalyst -No check engine light
  • High-flow design -Supports hybrid & large turbo power
  • Increases sound -Full and enriched exhaust note
  • Bolt-on direct fit -No cutting, no welding, no hassle
  • High quality -Stainless steel, TIG welded, & investment casting



IE's in-house engineered ProCore Catalyst features our own tri-core design with a specialized coating, enabling it to pass vehicle readiness monitors without triggering a check engine light. An advanced molecular bonded wash process applies the precious metal coatings to ensure long-life reliability. Whether you're looking to improve the exhaust note from your 3.0T or building a track-destroying hybrid turbo setup, enjoy your exhaust without the annoying check engine light.


No check engine light does not equal reduced power. The 6" 400CPSI CAT maintains optimal flow to support substantial power gains up to large and hybrid turbochargers. Your IE ProCore downpipe will pass vehicle readiness monitors and allow total and complete power, torque, and spool potential from your hardware and tuning upgrade investments.


Advanced 3D scanning tools and cutting-edge software provide our engineers with a high-resolution digital model of Audi's unique 3.0T engine. This data is then used to maximize the downpipe size for flow and ensure perfect and factory-like fitment.


IE downpipes are manufactured with quality materials for lasting strength and performance. The T304L stainless steel investment cast body smoothly transitions exhaust flow from the massive 6" CAT to the dual 2.5" mandrel bent exhaust legs. All joints are hand TIG welded using precise fixtures and tooling for a seamless, leak-free fit.


The stock downpipe becomes a significant restriction when upgrading to a larger hybrid turbo. IE's cast downpipe is a direct fit to available upgraded turbochargers on the market and will unleash the complete horsepower, torque, and spool potential from your turbocharger investment.

Our IE B9 3.0T intake systems, turbo inlet pipe, and downpipe are hybrid optimized, making the installation of popular turbo upgrades an easy bolt-in process.






2017-2023 (B9/B9.5)

3.0T (Turbocharged)



2017-2023 (B9/B9.5)

3.0T (Turbocharged)



Real-world power numbers are achieved using our in-house dyno cells to verify the efficiency of the downpipe design. Dyno testing performed in controlled conditions on a hybrid turbo equipped B9 S4 resulted in consistent and significant power gains of 45HP & 41FT-LBS to the wheels!


The following chart details the power gains (WHP & WTQ) over the baseline power numbers taken from the stock downpipe on our hybrid turbo development S4.
The "0" baseline is the maximum power/torque made, and each following increment is the additional power gained from the IE downpipe upgrade.

The above power gains are a result of various design details:

The 6" 400 CPSI ProCore CAT improves exhaust flow.

The increased size of the downpipe body and smooth transition into the midpipes quickly evacuates exhaust gases away from the turbine wheel, improving turbocharger speed and efficiency.

The thick-wall investment cast body reduces radiant heat keeping the engine bay and charge air cooler.

To learn more about each of these features, click the features tab above.



Install your new downpipe kit without welding, cutting, permanent modifications, or installation hassles. The process is straightforward with the correct tools. If desired, the factory heatshield and engine cover reinstall with a perfect fit for a truly stealth look.

Install time around 2-3 hours

Our policy lasts 14 days. If 14 days have gone by since your purchase, unfortunately we can’t offer you a refund or exchange.

To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.


* Customer must pay for the shipping to the original manufacturer.

Several types of goods are exempt from being returned. Perishable goods such as food, flowers, newspapers or magazines cannot be returned. We also do not accept products that are intimate or sanitary goods, hazardous materials, or flammable liquids or gases.

Additional non-returnable items:

* Gift cards

To complete your return, we require a receipt or proof of purchase.

Please do not send your purchase back to the manufacturer.

There are certain situations where only partial refunds are granted: (if applicable)

* Book with obvious signs of use

* Any item not in its original condition, is damaged or missing parts for reasons not due to our error.

* Any item that is returned more than 14 days after delivery

Refunds (if applicable)

Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund.

If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.

Late or missing refunds (if applicable)

If you haven’t received a refund yet, first check your bank account again.

Then contact your credit card company, it may take some time before your refund is officially posted.

Next contact your bank. There is often some processing time before a refund is posted.

If you’ve done all of this and you still have not received your refund yet, please contact us at


We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at labelled as “Defective Item”


If the item was marked as a gift when purchased and shipped directly to you, you’ll receive a gift credit for the value of your return. Once the returned item is received, a gift certificate will be mailed to you.

If the item wasn’t marked as a gift when purchased, or the gift giver had the order shipped to themselves to give to you later, we will send a refund to the gift giver and he will find out about your return.


You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of return shipping will be deducted from your refund.

Depending on where you live, the time it may take for your exchanged product to reach you, may vary.

If you are shipping an item over $75, you should consider using a trackable shipping service or purchasing shipping insurance. We don’t guarantee that we will receive your returned item.

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