EGR

Hello, it would be good to know what fails exactly. Over time the ducts from the escape multiple to the EGR valve are covered with carbon and ashes and that causes an insufficient flow of recirculation gases, which detects the computing and marks the check Engine. You have to uncover it or clean well. Likewise, the deposits accumulate in the EGR valve seat and prevent it from closing completely when it should do so. The check will ignite you in this case and you must clean it. If the valve opens and closes by means of a solenoid, you can try if it does not fail electrically. In another case you can apply an empty to the valve and see if then work. Applying empty in idle the engine will start unemployed until it is going to turn off if the EGRr is fine.
I think it is good to keep this system working well, since it helps a lot to reduce NOX emissions. This is because the low combustion temperature crosses recirculating gases and NOX are formed more more temperature. This also causes less thermal lost, means better fuel use. Another thing is that in Europe your car hardly will pass an environmental verification if the EGR is disabled. We here in Latin America still do not have this type of problem/control, and it is so easy to disable the system as disconnecting a plug.
If you can post the failures of the failures it will be easier to help you specifically, greetings

SOLUTION ,,,,,, Cancel the EGR valve leaves it closed ,,,, (0) circulation, and you will see how to improve the engine luck !!!!!!!