Originally Posted by NickTurnon

Your first breather mod is the most important and you will see the most gains. Anything you add after that wont be as significant without a tune.

For example, with CAI- (10-15hp) Test Pipes (8-10hp) Exhaust (5-15hp)

Ill be generous and say that you potentially gained +25 hp from the following mods, but with proper tuning, you will see another 10-15hp or more with a proper tune.

You can also do things such as valet, delete the rev limiter, delete the top speed, add security start, and you can also see increased MPG.