I have been getting a CEL with a P1401 code, I took it to the dealer and they did a $100 diagnostic and told me they "pinpointed" the problem to the DPFE sensor. After buying a Ford sensor for $63, I replaced it and still have the CEL. Do I need to reset the CEL and what is involved in cleaning the system?
2001 F150 Lariat, 4.6L. 192,000 miles

 

Here is a case for the lack of information both from the dealer and your position.
First, what is a 1401 code? It discribes a system test failure for exhaust flow rate between the exhaust manifold and the intake manifold.
The hardware should be tested/checked before assuming a faulty DPFE.
The fault can be any one or more parts of the EGR.
The EGR, the EVR, the DPFE, the ports in the intake past the EGR, not allowing flow or the abilty to measure it (the DPFE).
Clear the code, then see if it comes back after 2 drive cycles.
If yes you have not cleared the fault.
I suspect not allowing the dealer shop to do the repair has resulted in their taking a position of not being of any further help because they lost the shop work. If they were allowed to complete the work, at least they would have to review the situation until they got it corrected.
You took a chance and lost, so far.
The above info should let you know there is more to it than making a decision, without full testing and inspection.
Please do a search here for this code and you will find info on testing the EGR, cleaning the ports etc., so a lot of typing is avoided.
The board is also for self help so you can learn.
Good luck.

 

I appreciate your answering, let me see what I have!

 

Just FYI, I brought the truck in to the dealer to have the coolant flushed and a quick inspection. I told him that I had a CEL but not to worry, I was going to pick up a DPFE sensor from the parts dept and install it. He said that's a mistake because it's a big system and a lot of things could be wrong. He assured me they could "pinpoint" the problem with a $100 diagnostic. I agreed thinking for a hundred dollars it might save a lot of time. When he told me the DPFE sensor was bad and it would cost $250 to replace I thought that was excessive, I asked him to waive the $100 diagnostic charge and I would pay the $250, he told me that they can't just waive charges. The part costs $63 at ford and $36 at autozone and installation time is approximately 15 minutes. I was going to start with the sensor prior to the appointment and that would have saved me $100, if I had them install it, it would have cost $350. I'm going out know to clear the codes. When I was installing the sensor I noticed alot of carbon in the area on the outside of hoses and on the woven heat shield surrounding a approx 1" dia hose. Is this normal or do I possibly have a leak, I don't hear one but...

 

Pull the throttle body and clean the 2 EGR ports, they will probably be full of carbon. FYI, the Ford DPFE is worth the extra couple of bucks over the AZ DPFE. It will work better and last much longer.