Need a replacement catalytic converter for your 2004 Audi S4? MagnaFlow offers high-quality catalytic converters engineered for 2004 Audi S4 sub-models and engine sizes. We combine efficient design and state-of-the-art manufacturing to meet or exceed required emissions standards. Select your 2004 Audi S4 requirements and state vehicle registration to buy the best S4 catalytic converter online that fits your '04 S4 and meets your state’s emissions compliance.

MagnaFlow offers complete performance exhaust systems for your 2004 Audi S4. Determine the power and sound you demand for your 2004 S4 and shop all available exhaust systems online. Select your '04 Audi S4 sub-model and engine details to buy the best exhaust system that fits your needs.