The exhaust system consists of the following elements: two exhaust pipes converging into one in front of the catalytic converter. On vehicles 320i, 323i, 328i, a pre-catalytic converter is installed in the exhaust pipes. This is followed by the central and additional mufflers. In gasoline engines, oxygen sensors are installed before and after the catalytic converter to control the composition of the exhaust gases.
The downpipe is connected to the exhaust manifold, and for a diesel engine with a turbocharger. During repair, these elements can be replaced separately.