well i just added a apc filter to mine. I took out the old stock square box filter and the tubing. I just used the hose from the fuel injector, and went and got some pcv pipe and a elbow and a connecter and bought the filter. which is blue.LOL and i dont know if have noticed any difference, i did use alot of gas in 2 days though, i think thats from me racing too though,shhh,anyways who cares they look cool when you pop the hood, right