CTS Turbo 2018+ B9 Audi S4/S5 V6T 3.0T (EA839) HIGH-FLOW CAT

CTS Turbo's high-flow catalytic converter transforms exhaust flow on the B9 platform S4 and S5 fitted with the EA839 3.0-litre V6 turbo engine. Engineered to reduce backpressure that limits throttle response and peak performance, this catalyst uses a larger-cell substrate that flows significantly better than the factory restriction. Essential for vehicles undergoing ECU calibration or turbo upgrades, it maintains catalytic function whilst unlocking improved exhaust velocity. Direct bolt-in replacement suits 2018 through 2021 model years across both S4 and S5 variants.