I currently just got done with a rebuild on my 97 rs-t. I think I have a vacuum leak somewhere or forgot to hook all the vacuum lines back up. I blocked off my egr valve also, would that have anything to do with it? I think what I need is someone to tell me what lines hook up to the manifold from where. I have the vacuum diagrams from both chilton and under my hood. But, for some strange reason they are different. Any oh yeah, what the f*ck is that black box under the intake manifold and where do those 2 lines run????

http://forums.2gnt.com/dcboard.php?az=show_topic&forum=4&topic_id=67501&mode=full

How do the two diagrams differ? The diagram for the 95 in Chiltons will show a FPR on the end of the fuel rail with a vac line for it, but your 97 doesn't have that.

**EDIT**
Blocking off the EGR won't cause it, unless you didn't completely block it off and it's leaking there.