Originally Posted by scoobie_noobie
I have a 2005 WRX, Cobb access port, nothing more...yet. Well not that affects this particular thread anyway.
Right, you shouldn't be posting this question here.
Short answer is: you will get a little more power but gas mileage (efficiency), will really suffer. You won't particularly be hurting the engine but will be throwing money down the down the exhaust in the form of unburned gas.