The iE ProCore Downpipe for the Audi B9 A4 or A5 delivers an improved exhaust note with a massive increase in exhaust flow. Our unique in-house-engineered 4.75" 200 CPI catalytic converter channels substantial flow to support beyond Stage 2 tuning and upgraded turbos. The specialty ProCore CAT design includes rare and precious metal coatings that clean and limit emissions output to align with factory ECU requirements. so that you can upgrade without the check engine light.

Our in-house engineered ProCore Catalyst design features a specialized coating that filters and cleans exhaust gasses instead of a denser flow-killing cell count. This emissions coating process aligns with factory emissions output, 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 A4 or building a big power, big boost setup, enjoy your exhaust without the annoying check engine light.

No check engine light does not equal reduced power. The 4.75" 200 CPI 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.

The stock B9 2.0T downpipe becomes a significant restriction when upgrading beyond Stage 1 power. iE's ProCore downpipe is a direct fit to stock and hybrid turbos and stock or iE A4 Catback Exhaust System, giving you access to the complete horsepower, torque, and spool potential from your build.

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 full Stage 2 equipped B9 A4 (Procore Downpipe, iE Intake System, iE FDS Intercooler, & Stage 2 tune) resulted in consistent and significant power gains of up to 126HP & 183TQ over stock!