I started with the EGR sensor and have replaced the egr valve and the solenoid , I have also pulled the throttle body and cleaned the ports , I have cleaned or replaced all the hoses and the line from the exhaust to the egr valve and the CHECK ENG LIGHT is still on , Is there anyone that can tell me what I might have missed , my mechanic is stumped . Thanks

 

Clogged ports in the throttle body are the usual cause of a P0401. If that doesn't work, the DPFE is the next potential culprit.

 

I've cleaned the ports and the lines and hoses , what are the chances I got a faulty sensor

 

The DPFE is the sensor.

 

Iknow the DPFE is the sensor , I'm just thinking that I may have purchased a faulty one . I have replaced and cleaned everything else including the DPFE and the trottle body ports , what else could it be

 

Ahhhh. Are you sure it's still the same code? Maybe try resetting the computer and read the code again. I'm not sure what else will cause a P0401, the ports/DPFE will fix it 99% of the time.

 

When you replaced the DPFE, did you use a Ford part or an aftermarket part? Ford has done some updates to this part that the aftermarket parts don't have. They tend to work better. might try one if you used aftermarket. Good luck!