Good Day All,

First post to this forum, hope you can help. I have a '99 F150 5.4, 60k miles, engine light came on, read the code, got a 0402. Dealer told me to change the EGR valve, sounded resonable per the code. Did it , reset the code and now getting code 0401. Dealer said its either O2 sensor or Mass flow sensor. Not real confident with the dealer! Any sugestions would be appriciated!

Thanks in advance,

Dave

 

posts about carbon buildup in side the ports of the tube located at the throttle body thta goes to the EGR

 

This is what the ?Actron book says that P0401 is.

Did you also get a Ford code with this, or do you only have a generic scaner ?

I would have to concur with TexfordD on this.

If you replace the EGR valve, the inside of the back of the T/B might still be scaled up with the pimples that form there.

I have only seen people suggest to take the T/B off to clean these off the truck.

Try a look under jefflaws post list, I think he is the one that explained it.
https://www.f150online.com/forums/se...=&pagenumber=1

 

That only applies to a 4.6. The 5.4 doesnt clog up like that. (or we havent seen it yet)

You need to look at DPFE voltages while operating the egr valve by duty cycling the evr.

 

Thanks for the help. My next step was to check those voltages, will have to wait till I get back from the BGN race on Saturday.

Will keep you posted.

Dave

 

Checked the DPFE voltages, close to the limit so I changed it anyway. Seems to have cured the problem.

SSCULLY: I did use an ACTRON scanner adn those were the codes that the book gave me.

Thanks for the assistance.

Dave

 

Lot of good I did, read your book to you <g>

Glad to hear things seem better now, jefflaws is the man, even though he claims to be mainly an electronic and drivability tech.
That guy has forgotten more then I even knew about cars.

 

As soon as I read you went froma code 402 to a code 401 I knew it was the DPFE. That is exactly what my 4.6 did but I also had lots of carbon build up at the two EGR ports. I hadn't heard of the 5.4 doing that either but would agree it's possible. Isn't the 3.8 V6 bad about the EGR system clogging up too, why does Ford have so many problems with their EGR systems?

Glad you got it fixed.