A bad cat can cause engine problems, lower mileage, and impair performance. An OEM Mazda replacement can cost well over $800.00. A Pettit Racing Hi Flow cat can solve your problems while helping improve your airflow and releasing a little more of the distinctive ‘rotary sound’ that your 8 makes. Not only that but it will save you money while doing it! A direct replacement piece with a sensor ‘bung’ after the cat.