Japspeed's Silenced Decat Pipes for the Nissan 350Z replace the standard restrictive catalytic converters with two stainless steel, 2.5″ (63mm) one-piece items. Replacing the restrictive catalytic converters allows the exhaust gasses to flow much more freely, increasing the power output of the engine. Compared to our regular Decat Pipes compatible with the 350Z , our Silenced version minimises the increase in exhaust noise that fitting decats will cause.