APR B6, B7 Audi S4 4.2L Tiptronic Downpipes
This pair of performance downpipes is for B6 and B7 S4 4.2L tiptronic transmission vehicles.
These replace the 4-cat factory setup with a pair of metal matrix catalysts.
In testing, a full APR exhaust produces gains of 25hp and 35lb-ft across most of the engine powerband. Throttle response is also greatly improved.
These downpipes are designed to install to an APR exhaust but will work with other aftermarket exhaust or the factory exhaust with the use of adapters.