Patent ID: 8302306

Claim:
A method for making an exhaust gas treatment device for internal combustion engines, comprising: forming an inlet end cap configured for communication with incoming exhaust gas; forming an outlet end cap configured for communication with exiting exhaust gas; providing first and second substrates adapted to treat exhaust gas flowing through the exhaust gas treatment device; providing a gas sensor adapted to measure at least one characteristic of exhaust gas flowing through the exhaust gas treatment device; forming a cylindrically-shaped first housing member with a hollow interior, a first end shaped for operable connection with the inlet end cap, a second end having a radially reduced section, and a first radially extending aperture configured to receive a portion of the gas sensor therethrough; positioning the first substrate in the interior of the first housing member; connecting the first end of the first housing member with the inlet end cap to form an airtight seal therebetween; forming a cylindrically-shaped second housing member with a hollow interior, a first end shaped for operable connection with the outlet end cap, a second end having a radially enlarged section, and a second radially extending aperture configured to receive a portion of the gas sensor therethrough; positioning the second substrate in the interior of the second housing member; connecting the first end of the second housing member with the outlet end cap to form an airtight seal therebetween; positioning the enlarged section of the second housing member telescopingly over the second end of the first housing member, such that the first and second apertures are radially aligned; and forming an airtight seal between the enlarged section on the second housing member and the first housing member, whereby the reduced section of the first housing member and the enlarged section of the second housing member are spaced radially apart a predetermined distance to define therebetween an annularly-shaped space which thermally insulates an associated portion of the exhaust gas treatment device.