Need a replacement catalytic converter for your 1991 Ford Thunderbird? MagnaFlow offers high-quality catalytic converters engineered for 1991 Ford Thunderbird sub-models and engine sizes. We combine efficient design and state-of-the-art manufacturing to meet or exceed required emissions standards. Select your 1991 Ford Thunderbird requirements and state vehicle registration to buy the best Thunderbird catalytic converter online that fits your '91 Thunderbird and meets your state’s emissions compliance.