Comes with race pipe. Catalytic converter sold separately. Add on costs additional 149.00 . We call it a "system" because we have designed the 3" downpipe assembly with total upgradability in mind. We do this by incorporating the latest technology in materials and componentry. No comprimises have been made in building these assemblies. Large diamter T304 Stainless piping offers great life and durability. Hi precision CNC made flanges.