Another EGR problem, DPFE?

[Willard]

Ok, I have been having EGR problems for god knows how long now. Everything runs fine, I still have a CEL though. I have always had EGR codes, 332 and 335 come to mind. 332 means insufficient EGR flow and 335 is EGR circuit voltage out of range. Awhile ago, while trying to fix it, I ended up replacing everything. EGR valve, solenoid, and DPFE sensor. Since it's warmer out, and gas is expensive, I've started trying everything to find the issue again.

I tested the EGR valve, and it works flawlessly. I even applied vacuum with the engine idling, and the engine bogged down as it should.

I tested the solenoid, it give proper resistance, and the motor didn't run right after I hooked the hoses up backwards on accident, so it seems to work fine.

The only thing I found is that while running and hot, the DPFE still gives around ~.8 volts, which is what it is supposed to be when completely closed. The reference voltage is fine right around ~5.0 volts.

So I guess this means the DPFE is bad, even though its less than 6 months old? On the other hand, it never made a difference when it was new, so maybe I got a bad one from the start. I'm asking because I know things like the ECT can cause EGR problems as well. I tested the ECT at some point, and it's resistance seemed to be fine.

So, I guess, is it worth a shot throwing another DPFE at it? I'm tired of just throwing money at my problems, I want it to be the right part this time. Should I test the ECT again? I'm thinking about another DPFE, I want to be sure though. :scratch:

 

[boggs1227]

could always buy another and hook it but dont screw it down to the mounting plate and hook it up and run it long enough to see if thats the case...if not box it back up and say " sorry gave me the wrong part for the truck ...or some other excuse ?" autozone seems to be the best price on that at around $60

 

[Willard]

could always buy another and hook it but dont screw it down to the mounting plate and hook it up and run it long enough to see if thats the case...if not box it back up and say " sorry gave me the wrong part for the truck ...or some other excuse ?" autozone seems to be the best price on that at around $60

Yea, I think I may just do that. Hell, doesn't cost much more than a tank of gas

 

[MrShorty]

Have you checked the wiring? Remember that the computer can't usually tell the difference between a failed sensor and bad wiring.

Are those KOEO or CM codes?

 

[Willard]

I think those were CM codes, but they were cleared, and came back. I checked voltage to and from the sensor at the connector, so the wiring should be fine.

 

[Willard]

Ok, so I tested the DPFE again. The output voltage was almost 5.0 volts when cold and when hot. Completely different than the previous reading I got.

I'm wondering, the exhaust lines going to the sensor are always referred to as vacuum lines, so I guess they are supposed to have vaccuum? Mine definitely don't, but there is a noticeable flow there. Now I'm confused, and don't know if that sensor is bad after all.

I know someone provided a link a while back that talked about EGR systems in detail. Does anyone have that link?

 

[JohnJ]

The vacuum lines don't really have vacuum in them, no. They're called that because they look like regular rubber vacuum hose (but might be made of high temperature silicone rubber.) If the hoses are clogged or reversed or if the pipe they connect to is cracked you will get incorrect flow readings from the DPFE.

 

[Willard]

Hoses and EGR tube are all new, and they have flow coming through them. I also made sure they weren't backwards.

After reading a little more on how the DPFE works, it appears that I have a short in mine, since it is either on or off pretty much. There's no rhyme or reason to it being either way as well.

 

[Willard]

Alright, new DPFE from autozone (I know) and it sort of fixed things. I am down to one code, which is a godsend compared to what I've had in the past, and it's a 332 - Insufficient EGR flow detected. I know it works, manually applied vacuum to the valve and killed the motor. The only thing that gets me is that I watched the voltage while manually opening the EGR, and it barely changed, it went down to ~.5V from around ~.6V. I think it's supposed to go up.

So, it's better, but I think my problem either is something else (ect?) or the new DPFE won't cut it. If that's it I'll return it and find an OEM ford one to install.

What do you guys think?

C'mon here, this is killing me, I need suggestions!

 

[Willard]

Bumping again to mention the EVR, the resistance seemed to check out, but that is the only testing I did on it.

Anybody? help

 

[boggs1227]

when i was clearing out all the trouble codes on mine i ended up replaceing the dpfe,egr valve,new hose lines, and the egr vacuum regulator(whole dam thing ...really). first i replaced the valve thinking a simple fix but turned out the dpfe unit had corroded from the inside and then still could not clear out the egr trouble codes so i had to replace the vacuum regulator ,after that no more codes .so what i thought was one defective part turned into 3 !

and yes i checked with my volt meter to see if it was in spec and i think the egr regulator said it was ok as well ...thats why it took me a while to figure out that it must have been the regulator (figured i already replaced 2 parts already ...one more surelly will do it ) ..and it did .

 

[Willard]

Hmm.....it has been replaced recently as well. I will run more tests (tomorrow hoepfully) and see what I find. If that's the case, guess I'll replace it too. Man, this eats the wallet up. If it get's me better gas mileage, though, it'll be worth it. That should also be noted, my gas mileage is doing fairly good. Right around 15.

 

[boggs1227]

i know ... it cost me around $100 for all the egr parts .was it you or someone else that replaced the egr tube (from the exhaust) ?? if you did are you sure it's got a good seal (on the manifold end) ?

 

[Willard]

It was me who replaced the tube, since I broke it. It should have a good seal, but I can check that as well. I suppose it could have shaken loose before it rusted in place.

 

[Willard]

So I went out and looked things over again. The EVR is confirmed working. Put a vacuum gauge on it and the vacuum rose nicely with RPM's. Connected it to the EGR valve, and I think I can even hear it open and close that as well. Took some more readings from the DPFE, got something from it. Didn't get a light, except for once for a brief second. Only one code, 327, and I think it's because I disconnected the DPFE for a second. It could also be because I was messing with things so much, too. Either way, the light didn't stay on, so I guess I'll see what happens.

 

[Willard]

Ha, got the light back. I'm thinking the DPFE isn't changing when the motor revs up. The EGR valve is opening, but the DPFE doesn't know it. Either the crappy autozone DPFE just doesn't work, or the orifice in the tube isn't right. I'm wondering about that personally. I'm gonna try and see if there's a pressure difference myself.

 

[boggs1227]

Ha, got the light back. I'm thinking the DPFE isn't changing when the motor revs up. The EGR valve is opening, but the DPFE doesn't know it. Either the crappy autozone DPFE just doesn't work, or the orifice in the tube isn't right. I'm wondering about that personally. I'm gonna try and see if there's a pressure difference myself.

hmmm, i got mine at auto zone too......hey i know this sounds like a stupid question but for example my maf....i keep getting a cel and found out the wire harness (grabbers,the part of the harness that grips the socket and holds it in place) would not hold it's self on...had to tie wrap it tight.you sure it's not just that ...dumb i know but but maybe it's got a intermitant short in the harness.the orifice you mentioned the dpfe ones ?? or the egr tube ?? sure you did not buy one that goes on a ranger or something ?, do you still have the old one to compare (egr tube)?...could be sending the wrong pressure to the dpfe !?

if it's the dpfe at fault take it back for another . . . . . .

 

[Willard]

I think the wire harness is on right. The way it is acting now seems to confirm that it is. The orifice I'm referring to is the one inside the EGR tube, between where the two DPFE hoses connect. It should be the right tube, fits fine and everything. I wish I had the old one, but I don't. It was so mangled when I took it off, it was thrown away.

Btw boggs, thanks for all your replies.

 

[boggs1227]

no problem..... yeah i'm kinda tapped out on ideas .when i had my egr dillima...i just replaced all the crap and was good to go so i dunknow,sorry and good luck with it .

 

[Willard]

Yea, this one's a stumper. I'm pretty much to the point of leaving it, it runs better than it has in a long time anyways. I have no complaints with it, it's just the light is staring me in the face.