I was goin down the freeway and got my check engine light. When I got home and plugged into the computer and got code p0401 EGR insufficient flow... The truck runs fine, but I want to fix it... Ive been told to clean the build up out but dont know where to start, any ideas? And is this pretty common with 2003 F250 6.0?

 

pull the valve and clean. It is probably all sooted up and will not move freely.
Link is a great article to get you started:

Diesel Technician Society

 

Thanks, gonna try it today and see what happens, hopefully its all I need to do