[Tommy2tone]

My '98 SE just kicked off the SES light yesterday. Insufficient flow on the EGR. Car has 125K miles. Is this something that can be 'lived with' until it's convienient to service the problem? Does the EGR valve typicaly get carboned up, or just stop working good. Can it be cleaned?

Have not noticed the engine running poorly, but
we are going on a 1200 mile road trip starting tommoro.
Appreciate some quick advice

 

[izzmo]

My brothers SHO just picked this one up yesterday. It usually has to do with either a) a clogged EGR valve (coked up carbon) or a bad DPFE (differential pressure sensor).

First, I would check your EGR valve and see if it has any carbon build-up, if it does, clearn it up.

Second, go to your local store (Autozone, O'Reilly's, Advance, etc) and have them clear your codes. See if it pops back up. If it does, most likely you have a bad DPFE sensor then. RockAuto sells them for around $30 right now.

 

[Tommy2tone]

I forgot to tell AZ to clear code out of the OBD when they checked it. We were there to loan out the ball joint press and deal with the bj replacement last evening.
Will disconnecting the battery for a few minutes clear the codes?

Where is the DPFE located?

And will the big nut on the 'stove pipe' at bottom of EGR break free without twisting the pipe? We put a 1 1/16" wrench on it last night, and it felt like it was going to round off before it broke loose. So we stopped.

 

[izzmo]

You should have two bolts were it connects to the engine intake and then that should give you enough room to peak in and see if it has any build up.

The DPFE is located on the firewall, drivers side, right next to the break fluid resorvoir. It is a black box, maybe a couple inches wide with a few hoses coming out of it. A hose from your intake should be going to it.

 

[Tommy2tone]

Thanks Nick. Good tip on checking the EGR.

Sister does alot of road miles with almost no short trips, so I'm thinking not likely to be carbon build up.

Is there also a vacuum solinoid just for the EGR?

 

[izzmo]

There is, I'm not sure where this is, although I doubt this has gone bad, but it is always possible I suppose.

I would clear out the codes first and see if it re-appears. My brother had this appear and he has not seen it come back yet, so it might just be a fluke (1-time thing that was triggered for some unknown reason, and maybe there was something blocking EGR flow but it has gone away and code has just not been reset yet).

 

[Tommy2tone]

Yes, that is another possibility.
I had AZ check her Taurus SES light last winter and (we both) forgot all about dealing with it, as I was only visiting for the weekend. I'm pretty sure it was the same code. They probably cleared it that time, and it never came back on until yesterday.

 

[izzmo]

Most likely it is borderline flow (just enough volume in line to allow flow but just a hair away from not allowing flow). Hopefully that makes sense

I think a visual inspection just needs to be done. Also- highway miles (if you ask me anyway) are usually worse for carbon buildup because there is not as much fluctuation with the RPM and therefor airflow in the engine and can actually allow carbon to buildup easier than stop and go city traffic.

 

[360alaska]

my vote is for the dpfe, they always break...in all fords

 

[hydetherat]

my vote is for the dpfe, they always break...in all fords

YouTube - ‪Wells Ford EGR DPFE Training with Sgt. Tech P0400, P0401, P0402,‬‎

that is great info