DPFE = Differential Pressure Feedback Exhaust (sensor)

 

if the code is p0401 replace the dpfe sensor

 

thanks for all the info, guys ( or gals). i did end up changing the EGR valve and the sensor, and the light still came back on. i will try the suggestions in order of simplicity, and see what happens. i still only have 33K miles on the truck. seems to run fine. so i don't know if whatever is causing the light to be on, is hurting anything or not. does anyone know if it might be bad to drive while the light is on?
thanks again for taking time everyone...
dave

 

I still say try the fuel filter.. around 15 bucks and easy to change.. I changed my DPFE and also cleaned the ports and finially replaced the egr valve.. No luck.. Then somewhere on here someone suggested the fuel filter. IT WORKED! Just remember to use the fuel cutoff switch or else you will get a mouthfull of gas... (around 10 bucks in gas) lol

 

Don't forget, you also need a special tool to release the fuel line connectors. If you don't have one already, any auto parts store should have one.

 

you need someone to clear the codes form the pcm so the light will go out.it will not clear by itself. sometimes disconnecting the battery will work but not always.its not dangerous to drive around with the check engine light on but if something else happens with your emissions system you will not know there is something wrong because the light is still on. so have someone clear it and shut the light out.

 

But can someone tell me how a fuel filter can cause a P0401?