Need a replacement catalytic converter for your 2021 Ford F-550 Super Duty? MagnaFlow offers high-quality, OEM-Grade catalytic converters engineered for various 2021 F-550 Super Duty sub-models and engine sizes, designed to keep the check engine light off. We combine efficient design and state-of-the-art manufacturing to meet or exceed required emissions standards. To find the correct catalytic converter, select your 2021 Ford F-550 Super Duty sub-model and engine size, along with your state vehicle registration. This will ensure you purchase a converter that fits your vehicle and meets your state's emissions regulations.