Catalytic converters are notorious for being the most restrictive part of a car's exhaust system, and the 355 is no exception.  Put in place primarily for emissions control, most factory cats also do a great job of restricting exhaust flow and creating excessive back pressure.  In order to relieve this back pressure and provide a much more efficient exhaust flow on the 355, Tubi has developed these test pipes to eliminate the catalytic converters altogether.  The test pipes are a perfect compliment to the 355 5.2 insulated manifolds and Tubi Evolution muffler but are also designed to work perfectly with either factory Ferrari component.