The general parts involved are switch-over valves. One is for the EGR valve, the other is for the AIR divert valve (they are both located inside that goldish metal bracket). Vacuum is applied to the appropriate component (which is why there is a vacuum tube running to them) and each is individually controlled by the engine control module (which is why there are 2 wiring connectors). The small runner parts are kind of like filters. When the vacuum is released from these valves (control units shut off the EGR valve or AIR divert valve) they should shut immediately. The vacuum is released, and what you need to have happen is ordinary air to get sucked into the vacuum hoses rather quicky. So they install these filter parts so that you don't end up getting alot of dirt sucked into the vacuum hoses when the valve is deactivated. The air all comes through these filters.
I wouldn't sweat it all that much, you may even need to buy the valves to get new ones, maybe not.
Last edited by Gilly; 10-10-2003 at 08:33 PM.