Exhaust line of an exhaust system equipped with a catalytic converter for an internal combustion engine

A method for treating exhaust gas, from an internal combustion engine, comprising:

• (a) flowing said exhaust gas through an exhaust line, for an exhaust system having a catalytic converter, the exhaust line as viewed in a flow direction of exhaust gas from an internal combustion engine, being located upstream of the catalytic converter, adjacent to the engine, and having an externally located heat-conducting layer comprising a metallic material and a heat-insulating material layer internally located on the heat conducting layer, the heat-insulating layer and the heat-conducting layer being connected forcewise with another, wherein the heat-insulating layer and the heat-conducting layer are directly connected with one another, the heat-insulating layer is located inwardly of the exhaust pipe, the heat-insulating layer is arranged to be in direct contact with the exhaust gas, the heat-insulating layer is configured to have plural thin areas having a thickness reduced by at least about 10% from layer thickness of less than about 2 mm, whereby the thermal conductivity of the heat-insulating layer is sized to be less than about 106 J/(m3h), and the thermal diffusivity of the heat-insulating layer is sized to be less than about 0.01 cm2/s, and
• (b) flowing said exhaust gas through a catalytic converter connected to the exhaust line downstream with respect to exhaust flow.