Bad DPFE

[2stroke]

Weeks ago I replaced my DPFE and it solved all the engine problems I was having at the time. Just yesterday I was driving it, and it did the exact same thing again. It would drive fine, then randomly the engine would kind of load up and develop a miss. The power loss would cause me to loose speed, then it would instantly pop back into running good. Its really a weird thing. I bought one from O'Riley's last time, and I've heard aftermarket ones will not work on some fords. I heard they can go through 5 or 6 before that person would buy one from ford. The store will not take it back, or exchange it, and I can not afford a $170 one from ford right now. Is there anything else it can be? It has a code 327 now, it used to have a code 335 before the new DPFE. I don't need this vehicle to get around, its only for towing. I think it may be time it chugs its way into the junkyard.

 

[Jason94sport]

EGR. The tube may have little holes in them, another member is having that problem, or you can try to replace the EGR sensor.

 

[awood]

I know what you mean about the sensor. I had a different problem (It ran good, but I had a CEL light with "lean" codes - ended up being the PCM). During my troubleshooting, I tried a new DPFE just because I couldn't really find a good way to test it like I could with the Valve or Vacuum Switch. After fixing my problem, the EGR came back after a couple of weeks. I put the old sensor back in and it fixed the problem. The DPFE from O'Reilly's had failed after just a couple of weeks.

Try a junkyard part. Might be worth a try.

 

[2stroke]

Both the EGR valve and tube are less than 25,000 miles old, but I suppose the valve could be bad considering I run anything in the tank whether its just old gas I have, or often mixed gas in the fall. I don't remember the last time I took it to a gas station. Hypothetically speaking of course, what can I expect from the motor if I delete the entire EGR, and run a straight pipe for the cats?

 

[awood]

You could simply delete the EGR, but you'd have a CEL on all the time. The computer would be looking for a feedback signal after commanding the now removed EGR valve to open. If the feedback wasn't there, the PCM will set the light.

The following link is pretty good for troubleshooting Ford EGR systems. It's for a car, but the components are the same as the Explorer. You likely won't be able to test the DPFE like it shows in the video, but you can easily test the EGR valve and vacuum switch. You basically fool the switch into thinking the computer turned it on, which then opens the valve. At idle, the engine should stumble if everything is working, since the EGR should normally only work at a higher RPM.

If you have 10 minutes, it's worth a look...
https://www.youtube.com/watch?v=pH_kjRwD-Xw

 

[WOODSTOCK1962]

I'm having the same issue and found this info in another section. You will need a piece of tubing to connect the EGR vacuum line to the "REF" port of the DPFE sensor. Good luck.

1) Locate the DPFE Sensor (typically mounted on the drivers side valve cover).
2) Disconnect the two lines from the exhaust system and plug them.
3) Locate the EGR valve and disconnect the vacuum line from it.
4) Now take that vacuum line that was on the EGR valve and connect it to the "REF" port on the DPFE.( I think its the left port, but its marked REF)

Thats it. You are finished.

If your DPFE sensor is shot, this wont work and you will get a EGR related code. So its a good way to check that part.

This is how this works, when the ECU sends vacuum to the EGR valve to open it, the DPFE measures the differential pressure change in the exhaust and reports back to the ECU that the EGR did open and flow was detected.
By moving the vacuum line from the EGR to the REF port, the DPFE thinks that vacuum is the differential pressure in the exhaust and all is well.

So if you think your EGR is not closing correctly and allowing unregulated exhaust gas to enter the intake, try the above bypass along with this little procedure.

Remove the two bolts that connect the EGR to the intake tube. Now make yourself a homemade gasket (high temp material) that does not have the center hole. Bolt it all back up and your finished.

 

[2stroke]

I am still not clear. If I was to completely block off the egr using a plate at the top, and a bolt at the bottom, what will happen? Will it completely ruin the power of the motor, or just essentially turn it into a '93 motor? (no EGR)

 

[Bobmbx]

Check for clogs in both lines running to the DPFE. I found both hoses in a '99 Mounty were completely clogged from end to end with carbon.

 

[2stroke]

That's easy enough to check, but I just replaced the DPFE a few weeks ago. Does anyone know what will happen if I delete the EGR. And yes I know its not legal.