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.

Dual Magnaflow wide open mufflers with quad 3.5” exhaust tips, slightly louder and deeper than standard Borla. This upgrade option retains the large Borla resonator and replaces Borla mufflers with dual Magnaflow mufflers and quad tips. Borla is a great exhaust, but with this upgrade your back will look much better with the large aggressive oval quad tips and will sound better too! Cat-back exhaust systems refer to all of the components that exhaust gasses flow through after exiting the vehicle’s catalytic converter.

Engines fitted with regulated 3-way catalytic converters are equipped with a computerized closed-loop feedback fuel injection system using one or more oxygen sensors (also known as Lambda Sonds or sensors). Other variants combined three-way converters with carburetors equipped with feedback mixture control were used. An unregulated three-way converter features the same chemical processes but without the oxygen sensor, which meant higher NOx emissions, particularly under partial loads. These were low-cost solutions, typically used for retrofitting to older cars or for smaller, cheaper cars. Axle-back exhaust systems replace only your vehicle’s rear exhaust section, usually consisting of items behind the rear axles, like rear exhaust pipes, muffler, and exhaust tips. A&nbsp