I new to this, however i have a 97 f150 xlt 4.6 with 171,000 mile, which
has been getting a p401 engine code for about a year, it comes and goes
may stay off for one day and back again the next day, i have changed the
egr with one from auto zone, the dpfe with one from auto zone, all hoses
connecting them have been changed,i removed the throttle body, which was
pretty clean, and reinstalled with new gasket, i really don't know what to
try next, dose any one have any idea what to do next.

i am a old man 73 years and can to afford, to get a different truck, or
even pay the cost ford would charge to do the same thing as i have
already done

HELP,HELP,HELP

 

First, welcome to the site. I did a search for p401 and found this, click on it and see if that helps you:

https://www.f150online.com/forums/v8...ode-po401.html

If you want more to read, use the search feature. Click on the search button, above and to the right. Then click on advanced search. Then enter P401 code, and you will get lots of stuff to read.

Also, hopefully a guy named Jbrew will chime in, he knows a lot about these engines.

 

I moved the thread to the V8 Engine forum where maybe it will get more replies.

 

check the ports for clogging, did you reset the computer after you installed the new parts?? that's un-hook the battery and turn the headlight switch to "on" for about 20 minutes

 

Must be a typo in there somewhere, idunno.

 

The link Bluejay posted above is a great one. - temp1 has a pic of the elbow ports that get plugged on the 4six's.

f150mac -

It's one of two things or both lol -

1. Ports are clogged or close to it.

2. DPFE sensor. This is a dealership item ONLY!!!
Most third party shops stock defective DPFE Sensors. They either don't work from the get go, or they fail very quickly. Ford updated the replacement sensors, get them from the dealership.

 

I wondered who I was going to see, using the Camel 1st......

Ye, I read that post earlier about the disc./battery....head-lights on.

I let it go, figured Taraj was tired or something.

 

- Right! Jer must of had places to be, - or yea, his head fell on key board lol.

I know what he meant to say tho. After you disconnect the battery, Turning on the lights resets the KAM.

It's easier to do that then it is to pull fuse #28 for (our model only) or the PCM fuse(different fuse in other models) for a quick reset.

Actually, the quickest way to reset the KAM is to pull the negative and touch the the positive with it, then just reconnect the Neg. No, you won't blow up lol.

Other than that 20 - 30 minutes will do it.

 

If I didn't own a scan tool, I would rather wait the 20-30 minutes.

 

Out of my mind ? Well Maybe? - I really wouldn't say it if there was the slightest chance someone could get hurt.

But yea, it does sound funny don't it? Definitely wait the 20 if your not sure.

 

these hours are killing me,


I was just trying to help the feller out I didn't mean the lights would come on after he unhooked the battery but I figured he'd be able to figure it out

P.S. it's a llama