Doing this will cause a permanent "check engine" light. There is no performance to be gained from removing it either. The valve is only open during cruising situations where engine speed is constant for over 60 seconds at a time. The EGR valve re-routes combustion gases into the incomming air charge and has two positive side effects. The first and less important to us Mustang people is cleaner emissions. The second is cooler combustion chamber temperatures which lessens the chance of pre-ignition - especially important when running the engine at slow speeds and suddenly putting it under a heavy load by stepping on the throttle. A good example is passing another vehicle in overdrive. Any change in engine speed / throttle opening will close the valve. It is also NEVER open during idle, acceleration, wide open throttle, or decceleration.
The best thing to do is leave it alone. The ECM will think everything is great and life goes on.
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