Auxiliary catalytic converter having a back pressure relief device

An exhaust system for a vehicle having exhaust piping, said exhaust piping having an exhaust tailpipe with an open end, a main catalytic converter disposed in said exhaust piping, a muffler, and an auxiliary catalytic converter disposed in said exhaust piping, comprising:

• a) a main catalytic converter disposed in said exhaust piping;
• an auxiliary 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 auxiliary catalytic converter having an inner end and an outer end;
• b) said inner end of said auxiliary catalytic converter having tapered ends for insertion of said housing into said exhaust piping of said exhaust system;
• c) means for fixedly attaching said auxiliary catalytic converter to said exhaust system;
• and
• d) means for relieving back pressure within said exhaust system between said main catalytic converter and said auxiliary catalytic converter by diverting exhaust gases to bypass said auxiliary catalytic converter when the pressure of said exhaust gases at said inner end of said auxiliary catalytic converter increases above a predetermined pressure level, said means for relieving back pressure being located at said inner end of said auxiliary catalytic converter;
• wherein said means for relieving back pressure within said exhaust system includes a valve means selected from the group consisting of a bleed valve, a check valve, a pressure relief valve, and an electronically-controlled flow valve;
• and wherein said valve means includes means for maintaining the back pressure within said exhaust system at a level above 2 inches of water and below 7 inches of water.

An exhaust system for a vehicle having exhaust piping, said exhaust piping having an exhaust tailpipe, a catalytic converter disposed in said exhaust piping, and a muffler, comprising:

• a) a 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 catalytic converter having an inlet end and an outlet end;
• b) said catalytic converter being disposed within said exhaust piping of said exhaust system;
• and
• c) means for relieving back pressure within said exhaust system by diverting exhaust gases to bypass said catalytic converter when the pressure of said exhaust gases at said inlet end of said catalytic converter increases above a predetermined pressure level, said means for relieving back pressure being located at said inlet end of said catalytic converter;
• wherein said means for relieving back pressure within said exhaust system includes a valve means selected from the group consisting of a bleed valve, a check valve, A pressure relief valve, and an electronically-controlled flow valve;
• and wherein said valve means includes means for maintaining the back pressure within said exhaust system at a level above 2 inches of water and below 7 inches of water.