What is the part called that looks like a hydraulic underneath the filter box

The service engine light indicates your car's engine has an emissions fault that needs to be attended to or the engine is due a service due to mileage (oil change, inspection ect...). The warning light should be explained in your owner's manual. Check here http://repairpal.com/automobile-owners-manuals-online or try this link you may be able to down load a free copy of the owner's manual for your vehicle http://www.autousermanual.com/