UrS4boy

My diagram is a suggestion as to how to test the hoses between the turbo outlet and the Throttle body inlet (with all the appropriate disconnections and pluggings). With all those devices disconnected and things plugged you could test to 20 psi or above. Some people suggest just testing from the turbo outlet with no disconnections or pluggings (other than at the turbo outlet hose). I personally don't like that because then it potentially involves the PCV system as well. If you follow that route then I suggest only going to 10 psi.

As for an EGR valve, the the AAN does not have one. I just played with my 98 C4 Avant V6 EGR last week and all I can say about the AAN not having one is "Thank Gott im Himmel".