I came here did a search found some answers. I took the TB off and cleaned it and the same code came back. Then I replaced the DPFE cleared the code and after driving about 20-25 miles light id on. So would an exhaust leak by the manifold cause this?

 

Huh , that usually does it - 95 % of the time. - If your CEL came back on 20- 25 minutes after you rebooted, Then I doubt you have PO401 again. Scan and retrieve code/codes you have now.

Did you contaminate the EGR valve with any kind of cleaning agents ?

Suck test the valve yourself w/engine running.

 

I tested the valve and it is working. The engine just about died.

 

Well???, what about scan #2 ???

You rebooted the PCM after your first attempt correct ? You want help or not? -

I'll try this again , if you don't understand just ask. - You need to scan again for the code #'s ~ Code #'s = allot more info for us than just the little sentence after the numbers.

Don't leave anything out, - Something has been already, so help me help you figure out happened... - or didn't.

Good luck with it.

 

I stopped on may to work today and was told insufficient flow. I think I need to get my own scanner did not know there is more info then they were telling me.

 

Codes start with a "P" followed by 4 numbers. Ask whoever is doing the scan to give you the exact code.

 

Yea , he's not understanding.

Well, it's probably PO401.

Either the Plenum was cleaned incorrectly (if at all) or the DPFE didn't come from Ford.

Hard to say, - not giving us sh^t to go on :o

 

check your lines to the dpfe, they're often over looked and in sad shape. just a thought for now.

 

I checked the lines to the dpfe and they seem fine can blow air through them. I did buy the dpfe at ford dealer. What other info should i be looking for?

 

DPFE Lines connected correctly?

http://www.fordf150.net/howto/throttlebodyclean.php

https://www.f150online.com/forums/en...ttle-body.html


Hit this one time before you reboot -

http://www.fordf150.net/howto/clean-...low-sensor.php

 

I had an insufficient flow once upon a time that kept coming back and discovered (after replaceing EGR and other fun things) a hole in a vacuum line by the battery. 5 minutes worth of tube replace/glue and the light went off for good. Be sure to look over all your vacuum lines for cracks/leaks if you haven't already.

 

Another thing to check for on those DPFE hoses is whether or not the rubber inside the hoses is starting to flake off of the hose...especially on a 10-year old truck. Those little bits can get up inside the DPFE sensor and plug up the pressure transducers inside...fouling up even a new DPFE sensor. I dissected the "bad" DPFE off of my '97 and that's what I found in mine.

Don't try to replace the hose with just plain old rubber vacuum line material, the temperature will bake the stuff in no time. The correct hoses are made of a special high-temp silicone type rubber.

BTW, if you go to the dealership and order new hose, try to find a dealer (or parts house) that has the stuff in bulk instead of buying the cut-to-length ones specifically for your model. My current local dealer wanted around $130 for both hoses new for my '97 4.6L, but I called up the dealer that I used to frequent and they sold it to me in bulk for $10/ft. $22 was a lot cheaper than $130!

Besides what's already been mentioned...
If you still get the P0401, then it could be that the EGR tube (the metal one from the exhaust manifold to the EGR & has the two ports for the DPFE sensor) is clogged up with carbon or rust so that you're not getting exhaust up through the tube.
Could be the EGR valve itself isn't opening up smoothly or at all too...take a short piece of vacuum line hook it up to the actuator port on the valve and do the "suck test". You can open the valve manually this way and will notice a difference in how the engine runs with it open or closed.

 

I want to thank you all for the ideas,suggestions,tips, and links. I checked the vacuum lines and they're good. Then cleaned the MAF sensor. While it was drying I decided to check everything going to the DPFE one more time. So far the CEL has stayed off.