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An absorption muffler includes a metallic exhaust pipe including a plurality of perforations, a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, and including axially opposed ends. Thermal insulation is carried radially between the exhaust pipe and the polym

An absorption muffler includes a metallic exhaust pipe including a plurality of perforations, a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, and including axially opposed ends. Thermal insulation is carried radially between the exhaust pipe and the polymeric housing and axially between the axially opposed ends inclusive thereof. Acoustic insulation is carried between the thermal insulation and the polymeric housing.

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What is claimed is: 1. A muffler comprising: an exhaust pipe having a plurality of perforations and at least one pipe sealing flange extending generally radially outwardly; a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, the polymeric housing including (

What is claimed is: 1. A muffler comprising: an exhaust pipe having a plurality of perforations and at least one pipe sealing flange extending generally radially outwardly; a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, the polymeric housing including (a) at least one polymeric housing sealing flange integrally formed of the polymeric housing extending generally radially inwardly toward the exhaust pipe and spaced radially from the exhaust pipe and spaced axially from the at least one pipe sealing flange and (b) at least one polymeric divider wall integrally formed of the polymeric housing disposed within the polymeric housing that at least partially defines a plurality of acoustic chambers within the polymeric housing that each is disposed in fluid flow communication with a corresponding plurality of exhaust pipe perforations; and thermal insulation disposed axially between the at least one pipe sealing flange and the at least one housing sealing flange, radially between the at least one housing sealing flange and the exhaust pipe, and radially between the at least one pipe sealing flange and the housing. 2. The muffler of claim 1, further comprising: acoustic insulation disposed between the exhaust pipe and the housing including in each one of the plurality of acoustic chambers. 3. The muffler of claim 2, wherein the acoustic insulation is composed of a glass fiber batting and the thermal insulation is composed of a glass fiber sleeve. 4. The muffler of claim 1, wherein the housing includes a plurality of housing sealing flanges with the at least one pipe sealing flange therebetween. 5. The muffler of claim 4, wherein the at least one pipe sealing flange includes a plurality of annular pipe sealing flanges in alternating axial arrangement with the plurality of annular housing sealing flanges. 6. The muffler of claim 1, further comprising a trunk and axially opposed sealing ends including reduced diameter collars of the housing. 7. The muffler of claim 1, wherein the exhaust pipe is composed of metal, and the thermal insulation is composed of a glass fiber. 8. The muffler of claim 1, further comprising at least one clamping device circumscribing a portion of the housing. 9. The muffler of claim 1, wherein the plurality of perforations formed in the exhaust pipe includes a plurality of sets of perforations corresponding to the acoustic chambers with each one of the plurality of sets of perforations communicating with a corresponding one of the acoustic chambers. 10. The muffler of claim 1 wherein the at least one pipe sealing flange comprises an integral portion of the exhaust pipe formed by a bead upsetting operation. 11. An absorption muffler comprising: a metallic exhaust pipe including a plurality of perforations; a polymeric housing carried by the exhaust pipe and enclosing the plurality of perforations, the housing comprised of a tubular sidewall encircling the exhaust pipe and including axially opposed ends and at least one divider wall extending inwardly toward the exhaust pipe at least partially defining a plurality of exhaust gas sound attenuating acoustic chambers within the housing; thermal insulation disposed between the exhaust pipe and each one of the axially opposed ends of the polymeric housing; acoustic insulation disposed within the polymeric housing and received in at least one of the acoustic chambers; and wherein one of the plurality of acoustic chambers attenuates one frequency band and another one of the plurality of acoustic chambers attenuates another frequency band. 12. The absorption muffler of claim 11, wherein the housing includes at least one housing sealing flange and the exhaust pipe includes at least one pipe sealing flange adjacent and spaced from the at least one housing sealing flange. 13. The absorption muffler of claim 12 wherein the at least one pipe sealing flange is an integral portion of the exhaust pipe formed by a bead upsetting operation. 14. The absorption muffler of claim 11, wherein the housing is comprised of a plurality of the divider walls that extend radially inwardly from the housing sidewall, that are radially spaced from the exhaust pipe providing a space therebetween, and that at least partially define a plurality of the acoustic chambers therebetween. 15. The absorption muffler of claim 11, wherein the plurality of acoustic chambers and the plurality of perforations in the metallic exhaust pipe attenuate overlapping frequency bands and wherein the acoustic insulation provides another band of frequency attenuation in frequency range than the band of frequency attenuation provided by the at least one acoustic chamber in which the acoustic insulation is received. 16. The absorption muffler of claim 11 wherein the polymeric housing, including the tubular sidewall, axially opposed ends, and at least one divider wall is formed as a unit of one-piece, unitary, and substantially homogeneous polymeric construction. 17. The absorption muffler of claim 16 wherein the polymeric housing is formed of a plurality of clamshell halves that each have at least one generally axially or longitudinally extending mating surface. 18. The absorption muffler of claim 11 wherein the one of the plurality of acoustic chambers is configured with a size that is different than the another one of the plurality of acoustic chambers. 19. The absorption muffler of claim 18 wherein there is at least plurality of unequally spaced apart divider walls defining the differently sized acoustic chambers. 20. A polymeric housing for a muffler carried by an exhaust pipe having a plurality of perforations formed in a portion of the exhaust pipe, comprising: an outer shell comprised of a plurality of clamshell halves that engage one another along mating surfaces encompassing the plurality of perforations formed in the exhaust Pipe; a plurality of divider walls extending generally radially inwardly from each one of the clamshell halves toward an outer surface of the exhaust pipe; a pair of spaced apart ends; and wherein the plurality of ends and divider walls are axially spaced from one another at least partially defining a plurality of chambers therebetween in which acoustic insulation is received with each one of the plurality of chambers communicating with a corresponding plurality of the perforations formed in the exhaust pipe and providing frequency band attenuation that is overlapping from one of the plurality of chambers to another one of the plurality of chambers. 21. The polymeric housing of claim 20, and being composed of a polyimide material. 22. The polymeric housing of claim 20 wherein the ends each comprise an end wall and wherein the end walls and divider walls are unequally spaced from one another to at least partially define a plurality of differently sized chambers. 23. The polymeric housing of claim 20 wherein each end comprises a sealing end configured to cooperate with at least one sealing flange of the exhaust pipe comprises a bead-upset formed flange integrally formed of a portion of the exhaust pipe. 24. A polymeric housing for a muffler carried by an exhaust pipe having a plurality of perforations formed in a portion of the exhaust pipe, comprising: an outer tubular polymeric shell encompassing a portion of the exhaust pipe having the plurality of perforations, with the outer tubular polymeric shell having a pair of ends and at least one divider wall extending toward the exhaust pipe defining a plurality of acoustic chambers in which acoustic insulation is disposed; wherein one of the plurality acoustic chambers communicates with a first plurality of the perforations in the exhaust pipe and provides attenuation of a first frequency band and another one of the plurality of acoustic chambers communicates with a second plurality of perforations in the exhaust pipe and provides attenuation of a second frequency band; wherein the acoustic insulation attenuates a third frequency band; and wherein the outer tubular polymeric shell, including the pair of ends and at least one divider wall, is of one-piece, unitary, and substantially homogeneous polymeric construction. 25. The absorption muffler of claim 24 wherein the polymeric shell is formed of a plurality of clamshell halves that each have at least one mating surface with each clamshell half being of one-piece, unitary and substantially homogeneous construction. 26. The absorption muffler of claim 24 wherein each one of the plurality of acoustic chambers is configured to have a different size. 27. The absorption muffler of claim 26 wherein there is at least plurality of unequally spaced apart divider walls defining the differently sized acoustic chambers. 28. The absorption muffler of claim 24 wherein the plurality of acoustic chambers are configured so the first frequency band attenuated by the one of the plurality of acoustic chambers overlaps a portion of the second frequency band attenuated by the another one of the plurality of acoustic chambers and wherein the third frequency band attenuated by the acoustic insulation encompasses a frequency range that is broader than the first and second frequency bands and extends to a frequency higher than the highest frequency of the first and second frequency bands.