Looked at the TH Fix faq here:
http://www.contour.org/FAQ/FAQ.php?s=probs&displayid=3and had a question as to which hose I want to insert the cap in my 98 E0 SVT (seems like there are many versions of this assebmly).
In this picture of my assembly it seems most logical to choose location 4. Location 1 doesn't seem like it would work because there is no place for the cap between the 'tank' and inlet.