P0401 AND P0406

[Peter Brown]

Hey y'all, I cant seem to get rid of these above codes. So far, I've cleaned throttle body, replaced EGR valve, EGR control solenoid vacuum valve and the EGR pressure feedback sensor. My next move is to clean Mass Airflow Sensor. Any other ideas?
All The Best,
Peter

 

[Ozzy]

Things to check:

Is the EGR tube clear, no blockage?

Is there a vacuum leak?

Check the DFP sensor voltage. It can throw the 401.


Oz

‘05 Expedition EB, 5.4 3v

 

[Hamfisted]

What year, engine, mileage is on the Expy ?
The P0406 code is probably the DPFE sensor gone bad. That's the little flat-ish sensor there on the side of the throttle body with the two small hoses coming up off the EGR tube plugged into it. I'd try replacing that first and see if it clears up both your codes. Also inspect the two hoses that connect to it for cracks or deterioration, that might require replacing those hoses too. You can pick one up at any autoparts store, or Amazon or Rock Auto....

https://www.rockauto.com/en/catalog...sion,egr+pressure+feedback+(dpfe)+sensor,5088

https://www.rockauto.com/en/catalog...gr+pressure+feedback+(dpfe)+hose+/+pipe,10732

 

[Peter Brown]

What year, engine, mileage is on the Expy ?
The P0406 code is probably the DPFE sensor gone bad. That's the little flat-ish sensor there on the side of the throttle body with the two small hoses coming up off the EGR tube plugged into it. I'd try replacing that first and see if it clears up both your codes. Also inspect the two hoses that connect to it for cracks or deterioration, that might require replacing those hoses too. You can pick one up at any autoparts store, or Amazon or Rock Auto....

https://www.rockauto.com/en/catalog...sion,egr+pressure+feedback+(dpfe)+sensor,5088

https://www.rockauto.com/en/catalog...gr+pressure+feedback+(dpfe)+hose+/+pipe,10732

 

[Peter Brown]

Problem solved. Thanks all!

 

[Ozzy]

Problem solved. Thanks all!

Share the solution do it helps others down the road. Glad you’re fixed!


Oz

‘05 Expedition EB, 5.4 3v

 

[Trainmaster]

Just note that I more than once bought DPFE sensors that were bad out of the box.

 

[Peter Brown]

Share the solution do it helps others down the road. Glad you’re fixed!


Oz

‘05 Expedition EB, 5.4 3v

I changed my DPFE sensor with one from the dealer stealer for a 225% higher price than Rock Auto's least expensive, based on advice from Hamfisted. Check engine light gone! That Hamfisted dude has helped me big-time 3 times already.

 

[Peter Brown]

Share the solution do it helps others down the road. Glad you’re fixed!


Oz

‘05 Expedition EB, 5.4 3v

I changed my DPFE sensor with one from the dealer stealer, based on advice from Hamfisted. Check engine light gone!

 

[Peter Brown]

Just note that I more than once bought DPFE sensors that were bad out of the box.

Thanks. Your post compelled me to buy the Motorcraft part vs. aftermarket.