I've done this a couple times... the little one way valve can be sourced from the egr system on a 5.0 fox body mustang tbird etc late 80/early 90's. Just hacksaw the tube off and you can use it as well as the valve then some rubber hose and your done. Morosos site has the explanation of how and what angle to weld these on. Seems like the tube has to be in the exhaust pipe about 3/4 of an inch.