Another difference is with the material used in the cat-back exhaust system against that in stock exhaust systems. But the problem with a resonator is that it can cause restriction to the flow of the exhausts. In the end, this can end up lowering your vehicle’s performance. It is also more affordable and easier to install than other types of exhaust systems, including the cat-back exhaust system. Cat-back and axle-back exhaust systems are both aftermarket exhaust systems. A performance exhaust system, like the cat-back exhaust, allows for easy splitting into dual exhaust.
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