Need a replacement catalytic converter for your 2008 Audi S8? MagnaFlow offers high-quality catalytic converters engineered for 2008 Audi S8 sub-models and engine sizes. We combine efficient design and state-of-the-art manufacturing to meet or exceed required emissions standards. Select your 2008 Audi S8 requirements and state vehicle registration to buy the best S8 catalytic converter online that fits your '08 S8 and meets your state’s emissions compliance.