Is changing the egr valve something that can be done easily? If not how much do shops normally charge for this?

 

It's probably NOT the EGR valve - you can suck test it. Disconnect the vacuum line going to it, and with it idling, suck on it. The idle should drop.

P0401 is usually the DPFE or the lines going to it. If you replace the DPFE, use only a Ford part, aftermarkets don't last.

 

It sounds more complicated then I though I did a quick search on the whole DPFE-EGR system, and I will have to have a shop look at it. I know no problem is a little problem, but what happens if I don't bring it in right away? I'm short on cash right now, and I am working on selling my car is this something that I can wait to get worked on until my car is sold and have some extra cash?

 

My 4.2 was doing the same thing last year. Even after 2 complete and thorough tune ups. I wound up having to replace the intake manifold. You could also check the vacume lines. They dry-rot more often than you would think.