I have a 1997 f-150 with 93,000 miles. it is all stock with an auto trans. my problem is the egr code keeps coming up. I have changed the egr valve, egr sending unit, and the senser that pulls a vacumn on the egr valve. i was wondering if i missed anything. i am only getting about 9 miles to the gallon. i need any help i can get. thanks in advance,

Rodney.

 

I have a 5.4L and i'm starting to get the same error. I tried to clean the EGR valve and still got it I guess it's locked up. Any how I clean the thottle body at the same time and the part going to the egr value was so full of carbon it wasing funny. I used like 3 can of cleaner on it and my drimel. I mean it was like a pill of black sand I got out of there. Any how try cleaning it and see what happens don't forget to reset your computer.

 

Either a clogged EGR port or a faulty DPFE sensor will be the reason for over 90% of the P0401 codes.

Throwing other parts at that code will be a waste of money, especially when the diagnosis is so simple.

Steve