Need a replacement catalytic converter for your 2015 Audi S5? MagnaFlow offers high-quality catalytic converters engineered for 2015 Audi S5 sub-models and engine sizes. We combine efficient design and state-of-the-art manufacturing to meet or exceed required emissions standards. Select your 2015 Audi S5 requirements and state vehicle registration to buy the best S5 catalytic converter online that fits your '15 S5 and meets your state’s emissions compliance.