Instead of wasting money on an EGR valve, vaccum test it first.
With engine idling, apply a vacuum (vacuum pump or just pretend it's a milkshake) to the valve. A properly working valve with clear ports will cause the engine to stumble, even to the point that it might die.
Normally, it the engine does not react, the EGR ports behind the throttle body are clogged. Egr valves sometimes, but very rarely, will go bad, but usually they either stop seating properly or the diaphragm leaks vacuum.
Steve
