The Truck:
1998 F150 4.6, 2WD, 134K

My current saga:
CEL comes on. I have an OBD reader. It's the common 0401 code.
From the great advice I've gotten here:
Checked the PTFE and found the ports were plugged along with the the 2 Silicone hoses.
Replaced the original PTFE with a new one from NAPA (plastic version).
Cleaned the clay like crud from the hoses thoroughly and reinstalled correctly.
Reset the CEL codes.

Now the truck throws continual 1401 codes.
I've checked hoses and connectors for vacuum leaks (visually, & spraying carb cleaner and listening, etc). Nothing obvious.
Performed a complete throttle body removal, and EGR port cleaning. Wow, was it fouled. The amount of black carbon crud that came out was amazing.
Took longer to clean it than to take it off and put back on. And thanks to all that let me know that you must have a long 10mm socket!

This truck now runs GREAT.
Checked the IAC and recleaned (no idle problems but thought that it couldn't hurt).
Performed several CEL resets and yet I still keep getting CEL 1401.

Can it be the EGR valve is going (or gone)? I've read that these very rarely go bad, and I hate to just throw parts at a problem.

Can you suggest any other options to assist in diagnosing this problem?
Maybe with your help I can get this one licked.

Thank you all in advance for any consideration.

 

Any help? Anyone?

 

This 1401 code indicates an electrical fault in the circuit. Perform a visual check of the connector and wire harness to see if any wires are chaffed or cut.

JMC

 

Visually checked the wires to DPFE and that side and all looks good. No wires chaffed or cut.

Removed the 2 silicone high temp hoses that lead to the DPFE and started the truck to idle. Both hoses pushed exhaust flow out positively. Is that correct?

 

Can a faulty EGR Soleniod cause a 1401?

If so is there a way to tell if this needs replacement?

 

I came across your request on a different forum first and posted a lengthy answer there for you.

 

Your code indicates a specific failure here -

http://www.svtlightnings.com/scantoo...tc%20codes.htm

P1401= DPFE Circuit High Input (specifically)

If you have replaced this and still get the code you need to get the updated DPFE from the dealership ONLY . Ford updated this sensor for these reasons and you can ONLY purchase them from the dealerships as far as I know..

Good Luck

 

Yes; I got that...thank you! I will try to give that diagnosis a try.

Jbrew;
Thanks. If that PTFE indeed needs replacing with a Ford version I will do that and post back.

Thanks all...I will let you know what's what hopefully by Mon.

 

THE FOLLOWUP: ITS FIXED!!! At least I think so for now. No more CEL 1401 for 3 1/2 days (15 - 20 start/stop cycles).

The latest: I went through varied diagnostics (with the help of many of you here). Determined that the EGR valve is good, no vacuum leaks, nothing plugged, all wiring ok, and voltages correct, TB cleaned, EGR ports cleared, All hoses clear and checked for leaks/plugging, etc,etc...

Last thing...as suggested by one of you is top suspect the NEW NAPA DPFE sensor I changed out recently for an 0401 CEL code.
So; I go to take the high temp silicone hoses off this PTFE to take a look and break one of the plastic ends off. DRAT! I am a little steamed because I do not want to buy another new PTFE especially if that is not the problem.

You might not believe this but I took the OLD original ford DPFE and fixed it. No replaced, fixed.

Here's how (sorry no pics. I thought it was total folly at the time):

The body of the PTFE is held together by 6 recessed steel rivets.
Drilled them out enough to push the rivets out with nail punch. DONT drill all the way through the PTFE body as you will destroy some rubber gaskets you will need for re assembly.
Carefully pull apart the 2 body halves.
I noticed lots of white crud in there and blocked ports.
Used appropriately sized drill bits to clear the ports. To do this set body half in soft jaws of vice, You don't have to be jeweler delicate but don't be rough either.
Carefully pulled the ceramic sensor up (round white disk) and soaked body halves overnight in a 50/50 water/distilled vinegar solution in a small glass bowl. Also took a dental pic to remove any corrosion in gasket seats.
I propped up the sensor (kind of standing up) and taped so electronic components never touched the weak acid vinegar solution. Be careful no electronic parts touch your acid bath. I hope that makes sense?
Rinsed with fresh water and let dry completely (again, not the electrical parts).
Pushed the round whitish ceramic sensor back into position.
Put 2 outer body halves back together and drilled out the holes (no gaskets).
Separated the 2 halves and blew out any junk from drilling.
Installed the gaskets back carefully and put the 2 halves back together.
Used (6) 1 1/2" bolts and nuts to hold the 2 body halves together (any that fit will do).
Used a little of the Red LocTite on the bolts/nuts so it stays together.
Reinstalled the hoses and electric clip.
Reset codes.
Go for a drive or 3.

This sounds like a lot of work but its not. I spent longer figuring out what to do than actually doing it. Like I mentioned earlier If I was sure it was the DPFE that was bad, I would have replaced it but I had already layed out the clams for a brand new one about a week or so ago (and I don't want to be a parts hanger if I can help it).

When this PTFE goes bad again (and it probably will) my plan is to only replace it with the updated version from FORD. I'm going to think long and hard before I buy anything electrically related from NAPA again.

For those that provided opinions, assistance and diagnostics I can only say THANK YOU!!! You know who you are and have my admiration and sincerest appreciation.