Need a replacement catalytic converter for your 1990 Mitsubishi Sigma? MagnaFlow offers high-quality catalytic converters engineered for 1990 Mitsubishi Sigma sub-models and engine sizes. We combine efficient design and state-of-the-art manufacturing to meet or exceed required emissions standards. Select your 1990 Mitsubishi Sigma requirements and state vehicle registration to buy the best Sigma catalytic converter online that fits your '90 Sigma and meets your state’s emissions compliance.