two bolts to the engine and one for the tube that goes to the manifold.... comes right off.. you can then test it with a vacuum pump to see if opens and closes when it is suppose to....
if its not the EGR it could be the vacuum modulator or the carbon deposits behind the throttle plate valve.... do a search on this web site and it will give you the whole plan for cleaning the manifold behind the throttle plate/gasket area if you are getting the trouble code P0401.............
