An additional one has appeared in recent years, a very important aspect of the construction of manifolds and exhaust pipes, located near the engine. It is about the effective work of the catalytic afterburner, used in both gasoline and diesel engines (although its operation is different in both cases). The catalyst is working properly, when it's hot, It is therefore very important to heat it up to the working temperature as quickly as possible. To lose as little heat as possible from the exhaust gas in the pipes between the combustion chamber and the catalyst, they are built in two layers – pipe in pipe – a solution similar to a thermos. Another way to quickly heat the catalyst is to place the afterburner housing (at least preliminary) as close to the head as possible, this is not always possible. As a result, a modern exhaust manifold, especially large engine, it is a structurally very complicated part that is difficult to make.
The exhaust systems are not completely immune to vibrations, temperature and corrosion. The end silencers and connecting elements are most often damaged.