check engine light

[r37ribution]

The DPFE is just below the IAC on the drivers side of the vehicle. You might also try cleaning the MAF sensor. If you do a search and look at those posts for both MAF and DPFE you will find several pictures.

Thanks bro I know exactly where the MAF is and as for the DPFE I'm pretty sure I know what your talkin about now...I'll check that out later on tonight or tomorrow morning.

 

[Kingkobra]

ok so where is it located? and could it get contaminated with carbon like the EGR valve and the EGR position sensor?

If it can get contaminated could this cause an intermittent rough idle?

Yes ...it's right blow the IAC on the intake... the 2 rubber (actually silicone) hose could get plugged, but it is more common for the sensor to be bad.

Chk the hoses, if they are clear, test the voltage output to the PCM. You should be able to get specs for tet on the web...If not...email me and I'll look them up for you...

I can't see anyway for a DPFE to cause a rough idle, so I would look elsewhere for that...

 

[r37ribution]

Yes ...it's right blow the IAC on the intake... the 2 rubber (actually silicone) hose could get plugged, but it is more common for the sensor to be bad.

Chk the hoses, if they are clear, test the voltage output to the PCM. You should be able to get specs for tet on the web...If not...email me and I'll look them up for you...

I can't see anyway for a DPFE to cause a rough idle, so I would look elsewhere for that...

I had an EGR issue a while back with a very rough idle every time i started the car.

I replaced the EGR valve, the EGR sensor, the tubing from the metal EGR pipe to the EGR sensor, and I snaked the carbon out of the metal EGR tube.

I have been having some pretty nasty O2 issues lately and about 220 miles on a tank: 11.5mpg. I think the rich fuel may have caused my origional problem to resurface.

I'm pretty sure I can get the EGR voltage specs from the Ford dealer up the street. One of the guys in the parts department was having a smilar problem with EGR codes and the tech knew how to test to see which is faulty.

Reving the motor clears up the rough idle, so unless I leave my car running with the really rough idle (which sounds like its REALLY BAD for it) I don't think putting a volt meter on the output to the PCM is going to give me an answer (its not throwing a code). But on monday if I haven't fixed this I'll give that a shot.

 

[BuffaloXplorer]

Yeah, the DPFE is the EGR Valve Position Sensor screwed to the side of the intake.

The DPFE is NOT the egr position sensor... It's the Differential Pressure Feedback EGR sensor........ It doesn't measure anything except pressure, not position.....

Yeah, that was a typo...meant to say pressure but copied what he had written...

anyway...it's unfortunate to see another member (like me) trying to track down an EGR-related code that won't go the F$#@ away!

EGR voltage specs (i believe) are in the Haynes maual....they are DEFinitely somewhere on the forum, so do a search if in need.

 

[entinnovations]

CEL, Evaporator Emission system

CEL came on, took it to Autozone and they read it they didn't give me the code but said it was "Evaporator Emission System" something to do with purging the pressure fromt he gas tank the guy said. I had him erase the code, but four days later it came back on. Anyone know what this is or how to fix it? Would it be more helpful if I had the code? THanks for any help

 

[BuffaloXplorer]

Yes, the code would be more helpful...get the exact code and do a search for it here. You'll find something...

 

[jerrypar72]

EGR Code 0401

I have a 2001 Explorer Sport with a CEL on, and the code is 0401. The engine seems to be running just fine. The only thing I do notice is on acceleration, I hear a slight sputtering noise from the engine. It does sound like it is fuel related. I just take my foot off of the pedal for a second and then resume speed, and the sound goes away. Gas mileage doesn't seem to be affected. Do I necessarily need to change the EGR valve? Or is it OK to just live with the friggin CEL on?

 

[BuffaloXplorer]

EGR-related codes usually seem to be related to the DPFE sensor. In my case (402) it was none of the 3 major valves/sensors in the system.

Either 1. Have Autozone clear the code or 2. Unplug the battery for 20 mins to clear the code. Drive it until the code comes back. If this is the first time seeing this particular code, it's best to clear it and wait before throwing money away. Also, check the 2 hoses going to the DPFE. They sometimes become clogged or broken and are easy/cheap to replace - so cheap that you may want to just swap them anyway - Make sure you get EEC-rated hoses that withstand the exhaust temps!

The CEL may come back in 2, 20, 200miles or not at all. If it comes back, you could try the DPFE swap (buy from Autozone) and if the CEL comes back before you've dirtied up the new sensor, clean it off and return it to Autozone (here, they don't ask many Q's about returns, but if they do, tell'em your mechanic tested your existing one and it worked fine ). There's also the EVR (EGR Vacuum Regulator) and the valve itself.

Like i said, i've done all three to no avail. Aside from the 3 components and the hoses/vacuum lines, the manifold pipe that connects the egr to the engine may become carboned up - a thorough cleaning of this pipe (carb cleaner & bottle brush) may also help the issue. I haven't tried it yet, as i already did the EGR swap and would hate to take it apart again, but plan to soon.

Good luck with this...

 

[r37ribution]

... the manifold pipe that connects the egr to the engine may become carboned up - a thorough cleaning of this pipe (carb cleaner & bottle brush) may also help the issue. I haven't tried it yet, as i already did the EGR swap and would hate to take it apart again, but plan to soon.

Good luck with this...

After replacing the EGR position sensor (and the tubes), EGR valve, and snaking out the pipe for the valve that was the key to fixing my EGR issues a year ago...20,000 miles later, 3,000 of which were running at 11.5mpg :fire: my EGR issues return. No code tho. I plan on cleaning the EGR valve, EGR pipe, replacing both sets of tubes for the DPFE and EGR position sensor, and cleaning the DPFE (if possible)...

...and cross my fingers!

Anyone know if you can buy a EGR simulator like you can for the O2s?

 

[born2drive]

Good Evening-

Im having the same problems y'all are having. My CEL is on and from time to time the engine has a rough idle. I ran the codes and came up with

124- Throttle Position sensor voltage above normal
176- HOGO (HO2S) sensor fault/ always rich - very true by smell
- Insufficent TP change/ no sensor installed
177- HOGO (HO2S0 sensor fault/ always rich
- no oxygen sensor installed

I just bought two new oxygen sensors at Kragen and installed them. The check engine light is still on :fire: ... I have yet to run the codes to find out what now is the problem. I will do that tonight or tomorrow morning.

 

[Glacier991]

Ya know, I found a wonderful site online which clearly explained that in the On Board Diagnostic System (OBD-II as we know it now) the oxygen sensors are kinda like sentinels. They tell you what is going on... but when they give bad news, people blame them and replace em. They may just be telling you the truth, and something else is wrong. Good sensors get replaced a lot.

I pleaded to make that link a sticky.....or post it in useful threads so everyone could read it....maybe daily. Here is that link again....

http://www.explorerforum.com/forums/showthread.php?t=82038&highlight=Check+engine+light+myths

Please people, stop shooting the messenger.

 

[BuffaloXplorer]

...running at 11.5mpg :fire: my EGR issues return. No code tho. I plan on cleaning the EGR valve, EGR pipe, replacing both sets of tubes for the DPFE and EGR position sensor, and cleaning the DPFE (if possible)...

...and cross my fingers!

Without a code, y do u assume that your egr issues are back?

 

[born2drive]

...
"And the last Myth: The Check engine light means an O2 sensor problem.
Anyone who has taken this to be true and has spent quite a bit of money on replacing oxygen sensors knows this is not true.
First, you will not know, nor will anyone else, what the problem is until you have the trouble codes. Even if it is an oxygen sensor code, alot of times there are other causes for the code to come about."

whoops...

 

[r37ribution]

Without a code, y do u assume that your egr issues are back?

because the symptoms (intermit rough idle only on a warm start) are the exact same as before...only it wasn't intermittent, it was at EVERY warm start including sometimes on a cold start.

The code I got from the computer at the time was "EGR flow excessive" which explains why the motor was running rough at startup...It was being sufficated! I absolutely despise emissions! I hate them with a passion! They are the reason why my Probe wouldn't start AT ALL...an EGR issue (the Probe no longer has an EGR valve ). I have already replaced EVERY component of my EGR system except the DPFE sensor 3 times on my X trying to figure out what the hell was wrong last time. They were the cause of my past problems with my X and now they have resurfaced.

Think about it...an intermittent rough idle ONLY on a warm start. The rest of the time the motor runs flawlessly. Whats happening is the EGR valve is getting stuck open, therefore when starting the warm motor the PCM revs up the motor and then returns the R's immedialy to that of a normal idle. At this time the motor is sufficating from all the exhaust returning into the intake from the wide open EGR valve, causing a VERY rough idle. Reving the motor to 2,500 R's pushs enough exhaust thru the EGR system to free up the valve and eventually you get normal idle.

The reason it doesn't effect the motor on a cold start is self explainatory...the motors cold. The PCM keeps the R's up near 1,600 (or something) which is enough gas to prevent the motor from rough idle. Letting it idle at 1,600 R's is enough to free up the EGR valve on its own.

whoops...

check ALL your fuses both in your engine compartment and the interior fuse pannel. This was the source of my "O2 heating element manfunction" codes for ALL 3 O2 sensors.

 

[BuffaloXplorer]

...The code I got from the computer at the time was "EGR flow excessive" which explains why the motor was running rough at startup...It was being sufficated!....

That's funny - i've got absolutely none of the symptoms you describe...my 402 (egr excessive) comes & goes weekly (comes only at a stoplight/sign at idle) but causes no rough idle issues. I've yet to attempt to free up the manifold pipe for cleaning, but b/c i was able to "pass" my inspection it's not such a big deal (until November, when i have to really get it inspected )

 

[r37ribution]

That's funny - i've got absolutely none of the symptoms you describe...my 402 (egr excessive) comes & goes weekly (comes only at a stoplight/sign at idle) but causes no rough idle issues. I've yet to attempt to free up the manifold pipe for cleaning, but b/c i was able to "pass" my inspection it's not such a big deal (until November, when i have to really get it inspected )

The xplod3r that I was referring to is a '96 4.0L OHV. I also have a '97 5.0 with EGR issues and it has absolutely NONE of the symptoms that my 4.0 has. I believe the motors behave completely different when it comes to EGR problems. I don't think the 4.0 handles excessive exhaust flow anywhere near as well as the 5.0, it makes sense it's a bigger motor. It would still effect your fuel economy tho I would think.

 

[BuffaloXplorer]

I'm running the 96 OHV as well...

Last night i experienced first hand the symptoms you've described - it's never done it b4 - as i would have noticed the chugging. There were a couple different times that i noticed a surging/erratic idle when restarting while warm. I could even see it "pulsating" in the exhaust. I'm still quite certain that i've got a cat issue, as the info from my 3rd O2 sensor is showing the same results as the pre-cat sensors. I'm wondering if excess backpressure from a clogged/defective cat could be causing my issues...

 

[r37ribution]

Well I guess everybody is entitled to be wrong at times lol...

I replaced the EGR valve, snaked out the exhaust EGR tube, sprayed carburetor cleaner in EGR sensor tubes, the EGR sensor, the DPFE sensor tubes, and in the DPFE sensor.

I dunno if spraying carburetor cleaner in the DPFE or EGR sensor was all too great of an epiphany but I'm getting desperate so I did it newayz.

Before reinstalling all the components we tried starting the truck up with them all off. This of course threw a code and caused the truck to run extremely rough, exactly as it does occasionly when I start it. We then covered up the port coming from the EGR valve which leads to the intake mani with a cork and tried starting it...PERFECT IDLE!

I then reinstalled each part one by one individually, after each part went back on I gave her a 4-6 test starts to see if the rough idle came back. The DPFE sensor was the last part to go on and it seemed to start fine (you gotta remember this is an intermittent isu so this means nothing). Next, I disco'ed the battery terminal and touched it to the other side of the battery to clear all the codes.

But NoooOOOooo I still can't fix my problem. The good new is...when I do get the rough idle, it's not so rough haha! Which means to me that it's prolly one of the components that I cleaned. The only thing I haven't replaced yet is the DPFE sensor! aaahhhhhhleeeluuuuyaaahhh! I think we found the problem!

I think I'm going to return the EGR valve and save the money I would have spent on the DPFE sensor and put it towards an XCalibrator from www.xctflash.com or get Doug to program me a chip that doesn't utilize the EGR sensors or rear O2 sensor. I believe a truck with this many miles on my motor will be haunted by EGR issues for the rest of its life, and I shouldn't have to deal with that.

If there going to put emissions on our vehicles they need to make them reliable or we shouldn't have to use them at all! They're suppose to make us more healthy, well additional stress and headaches for something that makes your truck perform worse doesn't seem healthy at all to me! SO OFF THEY GO!

BuffaloXplorer: If this fixes my crappy 11.5mpg milage I'd recommend you do it as well!

 

[r37ribution]

BuffaloXplorer - I get my XCalibrator on tuesday from Doug. I think I already fixed my rough idle isues tho, but I still told Doug to take out the EGR system sensors.

I explained how I fixed it above, only in my above post I noted that I still had a rough (but smoother) idle. I believe that was because there was still a bunch of carb cleaner in the EVR (I don't know what this stands for but its on the same side of the intake manifold as the DPFE only closer to the firewall, just follow the vaccume line connected to the top of the EGR valve) selonoid or its vaccume tubes, possibly the DPFE as well. It runs cherry now

 

[zydeco]

I have a 1st gen X, that was giving egr flow excessive. After reading here and found out that the common prob was DPFE sensor. So I replaced that and no go. Replaced the hoses still no go. What finially fixed it for me was. the 2 hoses going to the DPFE sensor where on backwards. On my X the hoses cross, instead of going straight up to each port.

Zy