Exhaust Gas Recirculation Valve

 

What is the part that needs repair, and what does it do?

Your car has a system that puts any gas that remains after passing through the engine back into the gas tank. The EGR valve is a critical passage in this system.

 

How did this part get damaged or worn on my car?  What is wrong with it?

As more exhaust passes through the system, residue builds up in the valve, decreasing the size of the valve passage. 

 

What other problems can this issue cause?

A constricted EGR valve renders the system less efficient and decreases your car's gas mileage.  Depending on the severity of the residue buildup, the valve must be either cleaned or replaced to fix the problem.