I installed the new hose and IAC valve after they became available (with TSB #97-22-3). Made a slight difference in noise level, and no difference in the accompanying "surge w/AC on." In order to maximize the effect, you should take your car to a dealer and ask him to make sure your PCM is "flashed" with the latest code. I did all that, and the whole thing basically made very little difference.
Which is why the original pipe cap TH Fix is recommended in the first place.
