its kinda hard to screw up an intake install most intakes do his however there are different types of hisses there is a normal his and there is an air leaking hiss. Start your car up pop the hood. Or you can pop the hood then start the car that part doesnt really matter then just take your finger and gently slide it around the seals of the intake if the hissing goes away when your finger is at a certain area you have a leak there if you go over all the seals and still have the hiss then you just have a normal his that most high flow air filters have.