i am still out with the AIR RAID system, I took the sales rep that I had purchased it from and he said that was a long time problem that the early model 5.4 24v engines had, i thought to myself that hog wash. they should make a CAI that gives the proper punch with out all that vibration? what do you all think. what about AF1,true flow? like I said, I'm trying to fix my 04 4x4 up and the CAI sounds like a good start then a programmer some headers w/ H pipe and i am still unsure about the mufflers. any an all sugestion are very welcome. back when we us to crank up the power in on we did basicly the same thing but we did not have programmers and CAI. we flipped the breather and got a bigger cam & 4 barrel. I turely see how tech.. has taken off and left this old man in the dust.