B9 S4/S5 3.0T High-Flow Cat

The CTS Turbo B9 S4/S5 3.0T (EA839) high-flow cat is engineered to replace the restrictive factory catalytic converter, maximizing exhaust flow for significant power gains and an enhanced auditory experience. It is constructed from durable cast T304 stainless steel with hand TIG welding and back-purging to ensure longevity and reliable performance. The 200-cell steel high-flow race cat is specifically designed to unleash the performance potential of the 3.0T engine. Beyond performance, this high-flow cat significantly upgrades the exhaust note, providing a sporty growl and a more pronounced exhaust crackle on downshifts, especially when paired with an aftermarket exhaust system. Installation hardware is included to facilitate a smooth replacement process. **Important Note:** This product is sold for competition use only and is not legal for use in highway or street vehicles. Proper tuning software must be used to remove the check engine light (CEL) that will occur after installation.