I have an explorer with a 5.0 liter that I intend to sell soon. she has set off the check engine light. the code I am getting is 0401.

The "generic" manual states that it is:

Exhaust gas recirculation flow Insufficient detected


Any ideas on what is the cause and what is the fix?

Thanks,

Mike

 

Try doing a search on P0401

Cleaning the EGR valve might work, or it several other things. But this is a cheap/easy thing to try, so its a good place to start.

 

thanks for the info.

Mike

 

A P0401 is seldom caused by the EGR valve.

It is most often caused by either clogged EGR passages in the intake/throttle body or by a faulty DPFE sensor.

A simple vacuum test will tell you which direction to look.

Steve

 

The EGR valve is tested by applying vacuum to the EGR while idling. The engine should stumble or die.

If that tests OK, it is probably the DFPE sensor. I just installed one today, and I shook water out of it and the ports were almost clogged with corrosion. A bench test revealed very sluggish operation.

The DFPE is obviously a Break-A-Matic part, and is listed as a main source of problems on other Ford models as well. Suspect it anytime you get pinging on acceleration and you have cleaned the fuel injectors already.