Basically the same gains, but the stage II eliminates the codes thrown by aftermarket exhaust systems. Nothing to worry about unless you change your downpipe. The CAT-back exhausts won't throw the code.

Cheers!

 

oh thanks.

 

is the stage 2 any more agressive in tuning? or only to prevent the CEL?

 

Basically, it's the same tune. AFAIK, Your boost level won't change, and the only software change is the error code fix. Now having said that, after you have the full exhaust, your car will be faster. When you get the stage II then your tuner should log your car to adjust the timing and fueling to maximize performance. That will show improvement in horsepower, but mostly due to the exhaust, and not the increased tuning due to the second stage.

Cheers!