I found and repaired a sheared hose this morning but I wonder if someone can tell me what it actually comes from. Between plenum and false firewall to the left of the IAC valve a large round metal canister would be the best description. Two large rubber hoses bilaterally attached and a smaller one underneath leading away downwards, can't see where to. It was the small hose that had sheared. I managed to repair it, but if anyone can confirm what I have just repaired it might help me understand my car a little better!