Ranger1 wrote:
If you have an AutoZone nearby, they'll read the computer error codes for free. If not, you can retrieve them by cycling your ignition key from the OFF to ON 3 times in sequence. On is when the lights come on, not starting the engine.
Once you have the codes, post them and someone on this forum may be able to help. At least you'll be able to see if your dealership is working on the right issue. The fact that they already replaced the egr valve is a clue. If its the egr valve again, there are several well known codes that show up when it fails. Your repair order should have the TSB(s) and part numbers replaced. Post those as well - it may help someone here identify whats happening to your CRD.
Auto Zone will read the codes, but don't expect them to reset them. It's against their policy. I ran into this problem at the store here. Best bet is to buy your own scan tool so you can see what codes come up. I bought an Actron CP9125 for $79.99 at Advance Auto. It's a "Plain Jane" model that reads & erases the codes. You get a book that tells what the codes mean as well as a CD with code updates.