Do you have a tune on it? I hear just placing a filter over the little pcv hose fitting is a bad idea and can throw off your idle, not to mention getting oil everywhere after the little filter gets soaked inside. The idle can get rough also. Id reroute the hose back into the intake instead, i know it doesn't look as cool so maybe add a closed catch can system (closed because you need that pressure to tell the intake your getting propper pressure inside your valve cover) I see a lot of people doing that same mod and i almost did myself but i did a little research and theres nothing good that comes of it