Catalytic converter having pressurized-gas support means

Exhaust system, especially for motor vehicles, comprising an exhaust pipe and an exhaust gas purifying device of the type having a monolith of ceramic material carrying a catalyst, the monolith being disposed in a metallic housing having an inlet and an outlet for exhaust gas being purified, said monolith being supported only radially in a double walled mantle having a thin inner sheet metal wall closely encompassing the monolith and an outer housing wall, said double walled mantle defining the sole support, said inner and outer walls being connected at their longitudinal ends exclusively by sealing one wall to the other and defining between them an annular space, which is filled with gas under pressure, and a conduit connecting said annular space to a source of gas under pressure.