1.Remove EGR valve from the engine.
2.Check EGR pintle for carbon build-up and sticking. Use carburetor cleaner and compressed air to clean minor deposits.
3.Check the vacuum diaphragm for leaks with a handheld vacuum pump.
4.If a problem is found, replace the EGR valve.
5.Reinstall the EGR valve on the engine using a new base gasket.