Ferrari 355 (5.2/2.7) - Cat Spare Pipes***fits the Ferrari 355 (1996 1999) with Motronic 5. 2 (OBDII) and 1994 1995 Motronic 2. 7 (OBDI)*** Includes two O2 Sensor Bung Plugs for use on the 2. 7 Models. These lightweight test pipes fit in place of the heavy OEM catalytic converters. Using a test pipes removes the flow restriction a catalytic converter places on an exhaust system, while increasing the horsepower. The silencing effect of the converters are also removed, enhancing the