please help my cel came on p0401 egr flow. i replaced the egr and egr sensor and cleared the code. i drove the truck about 10 miles cel came back on p0401 egr. please help

 

I also have this pesky code on my truck currently. I have read in here that it could be the dpfe sensor as well as an egr problem. Try searching p0401 for more trouble shooting suggestions.

 

More then likley its your EGR passages in the throttle body that are blocked with carbon.Seems to be a common problem. Took me around a hour to clean,Have plenty of carb cleaner and long pipe cleaners on hand.

 

This fault has a lot of threads to check out.
It's a low flow test and easy to test out the system to come to a conclusion but a lot of words to discribe.
Pull the vac hose off the EGR and apply some vac to open the EGR while idling. If the engine gets rough, it's not the EGR or passges.
DPFE, hoses and metal tube are all that is left.
After cleaing and code clearing, it usually take 2 full cool down/ drive cycles to return if not repaired.

 

it was the DPFE but i did replace the egr and the egr sensor. will my gas mileage go up? before the cel light came on i was only getting about 12 mpg