Catalytic converter for a tailpipe including apparatus for relieving back pressure

An exhaust system of a vehicle having exhaust piping connected to an exhaust tailpipe, a main catalytic converter disposed in said exhaust piping, and a tailpipe catalytic converter for installing in said exhaust tailpipe, said exhaust tailpipe having an open end, comprising:

• a) a main catalytic converter disposed in said exhaust piping;
• a tailpipe catalytic converter including a housing having an exterior wall and an inner core of catalytic material disposed in said housing for chemically reducing pollutant gaseous emissions;
• said tailpipe catalytic converter having an inner end and an outer end;
• b) said inner end of said tailpipe catalytic converter being connected to the open end of said exhaust tailpipe, so that said housing extends from the open end of said exhaust tailpipe;
• c) means for fixedly attaching said tailpipe catalytic converter to said exhaust tailpipe;
• and
• d) means for relieving back pressure within said exhaust tailpipe between said main catalytic converter and said tailpipe catalytic converter by partially diverting exhaust gases to bypass said inner core when the exhaust pressure at said inner end of said tailpipe catalytic converter increases above a predetermined pressure level, said means for relieving back pressure being located at said inner end of said tailpipe catalytic converter;
• wherein said means for relieving back pressure within said exhaust tailpipe includes valve means selected from the group consisting of a bleed valve, a check valve and a pressure relief valve;
• and wherein said valve means maintains the back pressure within said exhaust tailpipe at a level above 2 inches of water and below 7 inches of water.