Main image shows "Dual Catted" variant. Inset shows "Catless" version.
The stock y-pipe with factory catalytic converters is a restrictive element in the GT-R's exhaust system. The COBB 3.5-inch Stainless Steel Y-Pipe is offered in both catless and high-flow cat versions that reduce exhaust restriction and allow the GT-R to make more power with less effort.
The catted version of the COBB 3.5-inch SS Y-Pipe uses custom-spun high-flow metal substrate catalytic converters that improve flow while protecting the environment by reducing emissions. The catless racing y-pipe is for off-road use only and deletes the catalytic converters entirely, further improving flow and allowing even more power.