havent had an issue since i put them on in 2009....
you sure the boot and/or clamps are seated properly when you install?? Did you pull the fuel rail to get the most access? I remember getting the #4 cyl (drivers side) on last and it was the most difficult. the bottom edge didnt want to go around the upper intake (part not attached to head). I put the couplers on the head side first, tightened those clamps and then started with #1 and worked my way across.