I actually skipped replacing the origional airt filter by putting in the TTP air intake, pretty much simular to the evo intake, just a little better craftmenship in my opinion. Air intakes are a nice addition, but be careful, I had to ultimatly have my ECU chip reprogrammed on a DYno, by the man Gunther so the car would run right. Air/fuel mixtures can be adversly affected if not done properly