Can someone please help me identify where this part could possibly connect to. I found it laying on the undertray. It looks like it blocked off something. I had taken the car in for service a few days prior. It could be related or unrelated, but my car is running with very rough idle at the moment.
Thanks for your time!

 

I would guess it was blocking off one of the many vacuum ports. You'll have to poke around and see where it is missing from. I would start around the area they were working on.

 

I'll keep looking but so far nothing apparent. I had my stock turbos replaced with 99 spec (still sequential setup) turbos, stock UIM replaced with polished UIM, and downpipe installed.

 

uhm, do u have the throttle body coolant lines disabled? It really looks like the stock tb coolant line cut and capped with a bolt. and that looks way to big for 90% of the vacuum ports. i think the only one that's somewhat that size is the line that goes to the brake booster. also, if the work you just had done was install new 99spec turbos and uim replacement you most likely have a vacuum leak somewhere. (since you idle now sucks)
check out the stick'd pages on the top of this forum for a link to the vacuum diagram threads.

 

Agreed, looks like the section of hose from the Throttle-body coolant line...presumably the section at the throttle-body since you'd know right away if the one behind the waterpump housing was missing w/o being plugged.

There's also a large bore vacuum port on the UIM next to the throttle-body. It faces toward the front of the car with a couple of smaller lines next to it.

 

Is that normally capped?

OK, thanks for responses. I'll check those out when I get home tonight.

 

no. it is a coolant hose, either to the throttle body, or maybe the turbos. if they put new water hoses on when they did the turbos (they should have! its a $10 part that lives in the hottest place and will take your motor if it fails)

anyways, if they put new turbo water hoses on like they should have that might be the old one

 

money