Your engine can only provide as much power as the smallest bottle neck in the breathing tract. Performance intakes, after-cat exhaust systems, and headers remove many of the restrictions in airflow that prevent optimized performance just shy of one element. The OBD II regimented catalytic converters are the one part of the breathing tract that are rarely addressed because of their delicate nature.
As you know, catalytic converters are designed to burn off any unspent fuel in the exhaust to lower emissions. The problem is that they inhibit performance because their design restricts airflow. Because this device has been standardized to accommodate new emissions laws, manufacturers don't spend the added money to tailor cats for specific vehicles. Instead, they get a few types to pass the California Air Resources Board (CARB), and they use these cats in their vehicles, based on engine size and performance.
Not many companies are brave enough to take the EPA head on, but MagnaFlow has decided to tackle the issue of clean, fast airflow with its OBD II-compliant performance cats. This means MagnaFlow has CARB-compliant cats for the three major domestic truck manufacturers. MagnaFlow's performance catalytic converters are also cheaper than the stock units, and provide added airflow, enhanced unspent fuel-burning ability, and a rugged design for the performance-minded enthusiasts. So, crank up the power and enjoy!