If you are refering to O2 eliminators, the easiest way to go are the ones from Dynojet. These will set you back about $30. You can also get 330 ohm resistors from Radio Shack for about $1 and use them in the same fashion, although not as clean of an install. I used the Radio Shack method first and later went with the Dynojet plugs for piece of mind. Both methods will have the same result. It will help smooth out the flat spots between 4-5K and when vtech engages. Heres a write-up on the 330ohm resistor install: http://www.vfrdiscussion.com/forum/index.php?showtopic=20350