Most designs of the time therefore included secondary air injection, which injected air into the exhaust stream. This increased the available oxygen, allowing the catalyst to function as intended. Cat-back exhaust systems replace every component behind the catalytic converter, including most piping, mufflers, resonators, and tailpipes.
Advanced 3D scanning tools and cutting-edge software provide our engineers with a high-resolution digital model of the Audi B9 S4 chassis. This data is then used to maximize the exhaust size for flow and optimize all available space for the perfect catback fitment. CORSA branded exhaust systems are backed by a Limited Lifetime warranty for as long as you own your vehicle with proof of purchase. The new exhaust sounds perfect, a marked improvement over stock. It is not too loud - I use the car as a daily driver and drive in capital beltway traffic.
There are subtle changes on the outside to let onlookers know that this is no ordinary F-150, such as a custom dual-intake hood, a custom front fascia and grille combo, and Shelby badging. For the interior, Shelby adds carbon-fiber trim, billet racing pedals, custom floor mats, and a serialized plaque. For lean-burn spark-ignition engines, an oxidation catalyst is used in the same manner as in a diesel engine. Emissions from lean burn spark ignition engines are very similar to emissions from a diesel compression ignition engine. Upon failure, a catalytic converter can be recycled into scrap.
By running pipes from the catalytic converter to the muffler and from the muffler to the exhaust tip, cat back exhaust systems improve exhaust gas flow, providing small performance boosts. However, your performance gains may be limited if your catalytic converter restricts gas flow, as a catback exhaust system is installed ‘downstream’ of the converter. Header-back systems are increasingly rare, namely because of modern emissions systems. Since removing your vehicle’s factory emissions components is highly illegal, the previous two options are more common. However, header-back systems are still available for some older, pre-emissions applications. In these cases, header-back systems offer more performance and volume than cat-back or axle-back systems