Downpipe sports catalysts 250 cells Capirsto Audi S8 D4 & S6/7 4G

Made of T309 (1.4828) grade stainless steel and hand polished to a mirror finish.

Inner diameter: Ø62, Outer diameter: Ø65

Replaces OEM part number 4G0254202NX and 4G0254252LX

These high-performance sports catalytic converters feature a 100 cell per square inch substrate made with highest quality materials currently available, designed to improve airflow for your vehicle and increase performance.

The cell count of a catalytic substrate refers to the number of holes per square inch and is a direct indication of the flow capabilities of that substrate. The fewer holes the larger the hole needs to be to fill a square inch, a larger hole subsequently lets more exhaust flow.

All this high flow won't be It helps if the substrate is "squeezed" into a small diameter container or tube. For this reason, CAPRISTO sport cats are packaged in 5.2-inch packages to maximize exhaust gas flow and operation of the valved exhaust system.

The CAPRISTO valved exhaust system helps torque at low rpm by providing back pressure in the exhaust and increases temperature for good operation of the catalytic converter. In the high-rpm open-valve condition, it takes full advantage of the free-flow characteristics of the CAPRISTO Sport Cats by optimizing high-energy exhaust at the ideal temperature and backpressure to maximize performance.

These catalytic converters can easily be fitted to a CAPRISTO exhaust system or any system that directly fits the OEM exhaust.

*Recommended for off-road and track use only*

Replacing the OEM catalytic converter may trigger a Check Engine Light (CEL).