arent the intakes CARB certified...for EMISSIONS purposes for use in cali and elsewhere...dont the manf have to test these things before they can sell them to the public?..contact your manf and see what they say..they will probably laugh like hell and ask you if your arse hurts...and a matter of fact, if our intake system is screwed up the little least...our cars WILL NOT RUN for sh!t..and for the cat...a cat is cat is a cat..go to a muffler shop and for 150 bucks or so and have them slap a high flow model on there and say F%^$ ford....a little more cooler, free flowing air isnt gonna hurt nothing anyway...