Patent ID: 7854296

Claim:
An internal combustion engine, comprising: a muffler attached to the engine, said muffler comprising a housing having an inlet, an outlet, and at least one auxiliary air inlet, said housing comprising a first chamber in fluid communication with said inlet and a second chamber in fluid communication with said outlet; an auxiliary air intake device associated with said muffler and disposed within said housing between said first chamber and said second chamber, said auxiliary air intake device comprising a single metal sheet having a stampable arcuate section therein with a restriction between a first end of the arcutate section and a second end of the arcutate section, wherein said metal sheet is affixed to a substantially planar inner wall of the housing such that at least one auxiliary air inlet embedded in the housing is positioned proximal to the restriction, wherein the first end is in fluid communication with said first chamber the second end is in fluid communication with said second chamber, and a fluid passage capable of producing a venturi effect is situated proximal the restriction, between first and second ends; a first catalytic converter disposed within said muffler housing upstream of said auxiliary air intake device; and a second catalytic converter disposed within said muffler housing downstream of said auxiliary air intake device, whereby exhaust gases passing through said auxiliary air intake device draw in auxiliary air directly across the housing and into the fluid passage through said at least one auxiliary air inlet prior to passing through said second catalytic converter.