Audi B9 A4/A5 2.0T High Flow Catalytic Converter And 3.0" Downpipe Kit

In stock
SKU: ES#3639508
Regular price $666.95

Product details

  • SKU ES#3639508

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Product Details

The perfect way to unleash hidden horsepower in a modern turbocharged engine is to upgrade the restrictive factory catalytic converter and resonator with a smoother, higher flowing unit. This is a great way to increase performance and add a nice growl to the exhaust note. Ideal performance is achieved through expelling exhaust gasses at maximum velocity through a larger internal diameter and a less-restrictive catalytic converter. We measured maximum gains of +14WHP and +13ft/lbs of torque on our Audi B9 A4 when equipped with APR Stage 1 ECU software, ECS Kohlefaser Luft-Technik Intake System and ECS Intercooler/Charge Pipe Kit. 

Through multiple design iterations and stringent product testing, we have engineered our High Flow Catalytic Converter and Downpipe to not only free up horsepower, but to provide trouble-free installation.  Designed and engineered in house, our High Flow Catalytic Converter and Downpipe utilize only premium materials and manufacturing techniques to deliver unmatched quality and reliability. Made of exquisite brushed T304 stainless steel and precision ground 3/8" thick CNC-Cut T304 stainless steel flanges, it is sure to look great and hold up to whatever is thrown at it.  New OE gaskets, class 10.9 bolts, and copper flanged lock nuts are included for a trouble free install.  Each weld joint is hand TIG welded for precision and strength and eye-catching beauty.  The stainless steel oxygen sensor bung is TIG welded in the OE-location so no extension harness are needed.  The downpipe features stainless steel flex section provides proper range of motion and heat expansion. The downpipe mounting point features a barbed hanger connection for a direct fit to the OEM downpipe mounting bushings to prevent disconnection.  A .065" wall thickness was chosen for reduced cabin noise and increased life span of the product

To complete our downpipe, we've included a 2.5"-3.0" expanded reducer with 2.5" Accu-Seal exhaust clamp that reduces to the OEM exhaust size. Please note that our downpipe ends at the factory clamping location and is 3.0" OD at this connection point. If using an aftermarket catback system some modifications or additional components may be needed. 

Our ECS Tuning High Flow Cat and Downpipe offer impressive real world results.  Get yours today and experience the difference!


  • Aftermarket ECU software is recommended to maximize performance gains as advertised.
  • This product will cause a MIL (Malfunction Indicator Lamp) on factory stock tune.
  • This product is in intended for off-road use only. Not intended for states our counties where regulations prohibit its use.

For a more aggressive exhaust sound, also check out our Center Resonator Delete, ES3576157.  Head over to our YouTube channel to see comparison video!