"B" piping on exhaust systems?

[gregshin]

can some answer this please?

[yenpit]

B-pipe is aka the intermediate pipe. usually goes from the cat conv back to the flange near the rear suspension, and has a small resonator (muffler) within it. it's the long pipe that comes with a cat-back exhaust system.

[gregshin]

does it do anything special?

[Tuck&Poke]

connects to the muffler... if you replace it you take out that little muffler and you get added hp

[yenpit]

its just part of the exhaust system. most cat-backs increase the pipe diameter and use a free-flow resonator. like minime said you can remove the resonator from ur stock pipe.....usually makes louder and possible nominal HP increase.