JIC 505 cat back exhausts are designed to increase airflow, provide better sound, and style to your car. The JIC catback added an additional 13 wheel horsepower alone. The exhausts are 3 inch with a angled out muffler, and include all hardware needed for installation. They DO have a bung for the factory 02 sensor. They are available in a full stainless steel, stainless steel with titanium muffler, or a full titanium. The Titanium weighs an incredible 8 lbs saving about 30lbs of weight on your car. Piping is 60mm with a 100mm tip.