Ford Repair: egr pressure sensor 2002 Ford explorer xlt, silicone hoses, dpfe

Question
Hi I have a 2002 Ford explorer .The service engine soon light came on today as soon as I turned the engine over.  I immediately went to auto zone to have a diagnostic done.  2 codes came up : P0401, and P0402.  All the possible errors listed are pointing toward an error in the EGR valve.  One errors says there is to much flow on the egr system, and the other says theres too little flow.  both list the EGR valve as a possible cause.  Logic would suggest that that is the cause out of all other possibilities.   What I need to know is can i fix this.  I am familiar with engines, however i will not tear this thing open.  I'm trying to sell this truck.  I'm not willing to ruin it to save some money.  If it's an easy fix no problem, if not I'd like to know how much to expect on having a Ford certified dealership fix the problem.  Also, is it safe to drive the truck under the circumstances?

Answer
It is 100% safe to drive.  However, the problem is not the EGR valve itself, rather it is the sensor that detects how much exhaust is flowing through the EGR valve.  This sensor is called a Delta Pressure Feedback EGR sensor (Or DPFE for short) and it is a small rectangular box attached to the side of the engine's intake.  It will have 2 silicone hoses and 1 wire connector attached to it, and the sensor should be black plastic.  They go bad all the time, and some are covered under extended warranties, so call Ford first as you may be able to get it fixed for free.  If not, the part itself usually costs around $70 and takes only a few minutes to install.  If you choose not to fix it, the only drawback will be lower fuel economy and an annoying light on the dash.  Hope this helps,
Jason