Im new to the import scene and Im confiused

 

a "catback" exhaust system is one that starts right after the catalytic converter and ends with the muffler. Basically the rear of the exhaust system. It does not include the catalytic converter or exhaust manifold.

 

Which is why it's called "catback"...since the piping is from the catalytic converter back. It took me a while to figure that out too.