Code 401

Recently the CEL came on oy my 2000 Windstar with a 3.8 andd 73000 miles on it. A trip to Auto Zone came up with "insufficent EGR airflow.'" The dude ther told me to remove the EGR and to shoot some Carb cleaner through it. I did that and also replaced the DPFE sensor. That seemed to work. The CEL cleared. After reading up on this in the Haynes manual, it says NOT to spray any solvent into the EGR because it could be destroyed. Now, 2 months later the CEL is back on, and another trip to Auto Zone and now I have a Code 401. Could I have ruined the EGR by spraying it with Carb cleaner the first time??

There are EGR ports, 1 for each cylinder.
The ports often clog....right where they enter the lower intake manifold.
The way to clean them is to remove the upper intake manifold, and physically clean them.
You do NOT want to spray cleaner into the DPFE.
Most likely, you did not harm the EGR valve by spraying in there...but it would be bad for the DPFE if it got into there (running down into the EGR tube before you got the engine started)

I have pictures of the EGR ports on my '96, which will look slightly different than your 2000, but the EGR ports are the same.

http://community.webshots.com/album/201931518cScpNK

Also, please look over the TSB covered in this website.
This would be worth doing, if not already done as it is a cause of the code you are getting.

http://leckemby.net/windstar/windstar01.html