The Mitsu logo is above the EGR Vacuum Solenoid Valve. Basically it has 12V on it when the engine is cold. Once it warms up it removes the 12V and the valve should go into an open state and allow the vacuum from the intake to operate the the EGR valve.
You should have a Vacuum diagram on the hood of your Tracker/Sidekick.
There is a picture of the part in question at
http://picasaweb.google.com/Drone637/MiscSuzukiPhotos/photo#5119372968624676178