Originally Posted by SouthArk370Z

To sum up some of the stuff in other threads: If you change the intake on a DD, you probably don't need a tune. If you change the exhaust on a DD, you probably don't need a tune. If you change the intake and the exhaust, you probably need a tune. The ECM will adjust for minor changes but can only do so much.

Personally, it doesn't make much sense to me to make engine/transmission mods without getting a tune. The tune from the factory is pretty good but there is room for improvement, even with no mods.