Ford Repair: egr system, ford exployer, egr flow

Question
i have a 1996 ford exployer with the 4.0 auto4 weeks ago the check eng. light came on with a code of p0402. i replaced the egr valve egr tube and egr vacuum reg.cleared the codes yesterday the check eng. light came back with a code of p0401. now iam at a loss. could it be the egr pressure feed back sensor? any help you could offer would be most welcome. sincerely robert mcdaniels.ps when i am just barely touching the gas peddle it sputters

Answer
Hello and thanks for the question...I'll try to help.
 I hate to ask this, but why in the world did you go and replace parts with out checking them out first? All a fault code is, is a starting point, unless it's a hard fault malfunction code. It is a not meant to be taken as a "what to replace" .........
 A P0401 is a insufficient EGR flow code. What you need to do is make sure that during a self test (Key On Engine Running), make sure the EGR is getting anough/proper vac. to open it. You'll need to remove the vac. line from the EGR and run the test.
Then, CHECK all of the vac. lines and fitting for the EGR system.
 Yes, it could be VERY possible that the PFE sensor is at fault. Check the inlet nipple and make sure it's NOT melted or clogged. If it isn't, that is the component that I would replace, seeing as you've repalced all of the pther EGR components before.
Hope this helps,
Erik