I doubt that the EGR valve is the problem. They are, however, a common fail item in the 40-60K mileage range, at least on the Hemi engines. Symptoms of a bad valve are hunting, almost stalling idle (it's not suppose to work at idle), low speed (35-50 mph) surging, and poor performance and economy. They go bad slowly like spark plugs, so you may not be aware of it until it sets a DTC. If you have a way of monitoring the EGR Commanded and EGR Error %ages, you'll see a bad valve fluctuating rapidly with unrealistic %ages (sometimes over 100%) at all speeds/throttle openings. A good valve still fluctuates, but not near as rapidly, and %ages at cruise are about 50-60% commanded with about plus or minus 0-10% error. A new valve runs $30-60, depending where you get it.
Have you checked/changed the PCV Valve lately? Have you had a peek behind the throttle body butterfly? If you haven't, take a look. I guarantee you'll be shocked. What I am getting at is that it could be a PCV valve "chattering" and amplifiying the sound through the intake. A new valve will stop that (install with the hole to the rear), and a catch can will eliminate the oily crap in the intake and behind the throttle body butterfly.
Also, back to the EGR system, the EGR Valve is a good thing as, when it's working, it lowers the combustion temperature, allowing the use of a little more timing. The DS folks did indeed remove it from their tuners for the reasons Lethal-Odor stated. The only way you can get it done now is through a DS CMR tune (~$300>) if you can find someone that will do it. If you cap it off you'll get a MIL and DTC.
