To be certain, I strongly recommend you:
* Consult your owner's manual: It should have a diagram showing the location of all major components.
* Use a repair manual: A Haynes or Chilton manual for your specific vehicle will have detailed diagrams and instructions.
* Look for it online: Search for "2000 Ford E250 4.2L EGR valve location" on YouTube or a reputable automotive website. Many videos show the location and removal process.
Remember to be cautious when working near hot engine components. Allow the engine to cool completely before attempting any inspection or repair.