Do any of you guys know what the term "cat back" or "turbo back" means on performance exhaust systems?

 

A cat back system is designed with the folks that want to remain emmision compliant or state inspection compliant. Or in some cases to save their warranty! The cat back exhaust systems only includes the peices from the Catalytic converter back.

The converter is a major restriction in the factory exhaust system and is in no way needed or helpful to the diesel engine.

The turbo back exhaust systems have the pipe from the turbo, all the way to the back to the end of the exhaust system. In some cases they also have provisions to allow the reinstallation of the converter into your new larger exhaust system. Turbo back allows for the most flow, and also eliminates the factory piping behind the turbo that often times is extremely restrictive!

 

too late, reference first post.