ok, so awhile back, my CEL came on, it was code p0401 for insufficient EGR flow. i posted this here....

https://www.ranger-forums.com/forum2...ighlight=p0401

from suggestions here, i replaced the DPFE and the CEL went away. not long after, the CEL came back on, so i decided i should probably replace the EGR valve. the light came back on. i went to Autozone and got the code read again, and now i'm getting p0402 for excessive egr flow. what's going on here? i need to get the truck inspected this month (Sept.) so any help is greatly appreciated.

 

First, spend some time at the Tomco site and learn how the EGR and DPFE work.

http://www.tomco-inc.com/techinfo.aspx

You may have a stuck open EGR solenoid. You may have another bad DPFE (I didn't read your link, so I don't know how long it has been installed). There are tests you can do and voltage readings you can backprobe, but I don't have any of that info at my fingertips. Try searching on DPFE and EGR and reading. You can learn a lot at that Tomco site.

It's almost NEVER a bad EGR valve though.

 

could it just be that the tubing is clogged?

 

also, not sure if this helps, but sometimes when i put it in park, the engine boggs way down like its going to stall. then comes up to a normal idle.

 

Try taking the vaccum line off the EGR valve and plug the disconnected line (so it's not a vaccum leak). Drive it that way and see how it acts, especially the idle dropping when you go in to Park.

If that makes an appreciable difference, I'd suspect your EGR Solenoid is stuck open.

Is there any possible chance that you incorrectly connected the vaccum lines onto the DPFE? They are slightly different sizes. Try switching them.

I don't think a clogged tube is your problem.

 

so saturday, i put in a bottle of STP Complete Fuel System Cleaner in to my half full gas tank. today, the light went off. not sure if the STP has cleaned the system and corrected the problem or not, but i'm on E now, so i'm sure it has gone through the system. we'll see if the light stays off.

 

hey ihave the same issues going. did the light come back? im guessing not because this is an old *** thread.

 

I originally had both codes P0401 P0402 show up. The car sat for 2yrs before I got it. Ive done a tuneup, fuel pump & filter, ERG, ERG Sensor, had my (throttle body, Intake, & cradle housing) professionally cleaned, new battery, alarm taken off and new terminal. The codes went off but my truck cranks all the way up and turns back off. After 2-3 times itll stall and I have to wait 45 min- 2hrs to crank again. Ive been through 4 mechanics! Can anyone help me

 

Well, I have two news, both not great but it is what it is. Gave the EGR system a good look see, moved stuff and replaced a questionable vacuum tube. Tried to find out how many inches of vacuum the diaphram on the EGR needed to do it's job. no answers so I just went for it, did the remove the neg. ground trick, crossed my fingers and fired it up. hooray for me, no cel . #2, one down now the tach doesn't work right, when you disconnect the ground like you are told, be extra careful, the smallest spark can affect the PCM. Be patient, give the PCM time to reset it's self. Done and done. Many thanks for all the help, yeah, I know, you're saying " you didn't know that?" Look up dumb and my picture is there. LOL. Thanks again.