The only power mod within the cobb stage 1 (other than the access port) is a High Flow Drop in Air Filter. While the part by itself does not produce any horsepower or torque; when accompanied by a tune this turns into a rather cost effective modification. The tune claims that it can bring up to 3% hp and 15% torque.
These high flow filters can be controversial due to their nature. It makes consumers question why the stock filter isn’t good enough. In addition to this if the other filter allows so much more air flow is it letting other debris through as well? Is there a reason the stock filter was thicker? So far none of these questions have lead to issues in the fiesta ST but in some of the older cars there were some serious concerns of debris getting into the engine.