got a code P0402 from the computer this morning for the CEL. egr excesive flow at idle
we know we need to clean the throttle body and egr passages behind the throttle body. should this take care of the problem?
it is the 99 SE Sport that we just got. Has 52k and was driven fairly easy. I had gotton on it a few times last night and then the light tripped when I was sitting in a line a traffic. I think some junk got stuck some place because the CEL turned off this morning.
I get this code all the time too, I just pull over and reset the code with my computer. I have already replaced the EGR valve, so I think its a vacuum problem in my case. Let me know what you find on his car. BTW, if the EGR is clogged or dirty, you can really only replace it, from what I remember, you cant clean these EGR's.
Brapple: clean the EGR passages first since it only costs a couple bucks for the stuff to do it and it's so easy to do. If that doesn't work I would replace the DPFE sensor, that is typically the problem.
99blacksesport: Your problem is most likely the DPFE sensor. They are relatively cheap and very simple to put on.
I cleaned the TB and passages and cleared my P0402. I recently got back from a 6000 mile (honest) trip to the midwest and it showed again, then went away! Let me know if you fix the problem.
Originally posted by SweetSVT99:
Brapple: clean the EGR passages first since it only costs a couple bucks for the stuff to do it and it's so easy to do. If that doesn't work I would replace the DPFE sensor, that is typically the problem.
my father is on his way to the dealer tomorrow to get brake pads for the new car ans some other small things. A set a throttle body gaskets are on the list to so both the 99's will have this done.
will let you know if anything comes of it
What is a DPFE sensor, wheres it located, what does it do, etc..? Thanks for the help! -Nick
Originally posted by 99blacksesport:
What is a DPFE sensor, wheres it located, what does it do, etc..?
Check here:
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=311440
If you do find it is the DPFE try getting one at discount (one of the sources that are mentioned on this site. I got one at cost $34.39 instead standard retail $75. From the same dealer only got a cousin with transmission shop, has an account. Get the new updated version Plastic F77Z-9J460-AB, it supposed to last long. This DPFE is a fun one the catch, even with shop CD and OBD II tool.
Paul
since you've got P0402 EGR flow at idle check the EGR solenoid, not only does it turn the vaccum on to operate the EGR the tiny filter inside allows the vaccum that EGR was operated with to vent. Even possible small piece of carbon holding the egr open slightly, however don't recall anyone actually saying that they found that.
It mine about six months of intermitents before the DPFE finally totally died. I even had 0401 & 0402 set at the same time once. insuffiecent & excessive
How would I check the DPFE is causing my P0402? My TB is clean, theres a fairly new EGR on her too. Thanks alot! -Nick
Beside the obvious visual check of the two hoses that connect the two ports on the EGR pipe, a scan tool (in my case an old laptop with OBD-2.com software) the Ford manual has a test you do that actually lets you read or look for a certain voltages.
Actully the PCM is doing it, the Scan tool is only part of the equation it sets up the PCM to do the test and gives a read out.
Something like that right Mr. Pappas?
George helped me chase mine down last year, nope, hmmmmmm just this spring I finally got it to totally fail.
This is one time I'm glad I invested in Alex Pepers OBD II device and software. It's almost a necessity with vehicles now. You can waste allot of money and time, still takes me allot of time and money but then I'm trying to train myself. I fiqure in 10 more years I might get it mastered, but then the Mystique will be 15 years old. Then I'll have to start all over. But then that's what a car buff does.
Paul
well after about two weeks, car was only driven one because we were waiting for rear brakes pads, the CEL came back on. It happened while I was parked, idling infront of a bank waiting for my friends to use the ATM.
I am going in a few minutes to get the code read again but I feel it is the same one.
I will look at our Ford Service Manual for our 95s in a while also but does anyone have a good way to test to see if the problem is the EGR valve or the DPFE sensor?
I went through this with my SE the first day I bought it. The light will come back. Perform the TB cleaning at your leisure.
I also had to replace the DPFE at the same time. I still had the original aluminum case DPFE on my car. The new DPFE was made of black plastic - probably recycled water pump impellers.
JimR
sorry if it wasn't clear but we have cleaned the throttle body hoping that would solve the problem
We think since the car idles fine it is not the EGR valve. So that would only leave the DPFE sensor right?
Originally posted by brapple:
sorry if it wasn't clear but we have cleaned the throttle body hoping that would solve the problem
We think since the car idles fine it is not the EGR valve. So that would only leave the DPFE sensor right?
Correct, sort of. If you want to check your EGR valve, just get a short length of tubing from the auto parts store. It should be a small diameter size to fit the nipple on the EGR valve.
1. Unplug the stock vac hose from the valve & plug in your blank length.
2. Start the car & put a vacuum on the tube (suck on it if you don't have a pump).
3. If the car stumbles or stalls the valve may be good. To verify:
4. Apply vacuum until the car stumbles, if you can hold a constant vac by pinching the hose to keep the car running rough then your valve is good, no leaks.
Now its time to focus on the DPFE.
The older aluminum body DPFE units had a tendency to accumulate corrosion & fail (like mine).
The DPFE is just a little tricky to get to, even though it is in plain sight just below the EGR valve. Its held in place with two bolts & has two vacuum hoses plugged into it. If you're just a little handy & your arms are not gorilla size this should be a 4 out of 10 on the difficulty scale - just keep track of the hoses (see my signature below).
Originally posted by brapple:
sorry if it wasn't clear but we have cleaned the throttle body hoping that would solve the problem
We think since the car idles fine it is not the EGR valve. So that would only leave the DPFE sensor right?
Did you clean all the passages? The TB itself isn't causing this problem, the clogged passages were the culprit on my car. Make sure you get ALL that crap out of there before you spend money on a part that won't fix the problem. I had the PO402, had to clean the passages twice before the CEL stayed off. I would give the cleaning one more shot.
my father did the cleaning so I don't know completly what he did but I am fairly certain that along with the throttle body he cleaned the passages behind the throttle body. He did this on his car after he got the throttle body off because he wanted to clean it
like I said I drove the car a week before the light came back on with the same code. infact it shut off this morning and turned back on when we pulled in our driveway tonight and the car just sat and idled very shortly
I'd hate to bring up an older thread - but the issues in this thread is what I'm experiencing right now.
I had a P0402 while idling in traffic. Car still ran fine. Reset PCM. P0402 came back after a day or two. Again while idling. Car ran and idled fine.
However, yesterday, I went to start her up - went inside to grab something I forgot and went back outside....car stalled.
Started her up fine - idled fine until it settled down to about 600rpm, then it stumbled like it would stall, but then catch itself.
I have an older aluminum DPFE sensor housing - and its in bad shape from its appearance.
What does the car stumbling like that indicate?
The EGR Valve is a PITA to change, isn't it? I quickly read the Haynes book last night and I have to remove the nut from the rear manifold.
Or do I? Any help??
Thanks.
the cel from idling in traffic sounds like what my problem was/is. my conclusion lead me to the dpfe sensor.
as for the bad idle that sounds like a egr valve, that can be tested by applying vac to it and see how it effects idle. a correctly working one will not effect idle I beleive.
be systematic when you check things and you should be able to find out what is wrong
OK. Well, I know all passages are clean since I just performed the Intake Overhaul including the TB less than 1k miles ago.
I don't have a vacuum pump - so by doing the test indicated above, the hose should go on the EGR valve itself - where the green vacuum line is normally located right?
What is done to the actual line when unplugged? Does that need to be plugged up?
Does a failing DPFE sensor cause any abnormalities in teh way the car runs, other than just tripping the CEL?
Thanks for the help.
as for the vac test I am not sure what exactly you do, I wasn't around when my father tested the egr valve. I suppose you would take one of the hoses off the dpfe and apply a vac to it
from what I saw a failing dpfe doesn't do much then throw a cel. I think the gas milage went way down but then again that could be my driving so I am not 100% sure
Originally posted by brapple:
as for the vac test I am not sure what exactly you do, I wasn't around when my father tested the egr valve. I suppose you would take one of the hoses off the dpfe and apply a vac to it
Yep. vac to EGR valve -> EGR valve opens -> engine coughs
and stalls at idle
(EGR is supposed to be closed at idle).
if you suspect the EGR system to be faulty and think that
the valve is not stuck open, you can disable the whole system temporarily.
I don't exactly remember how to do it, but I guess all you
have to do is disable the solenoid by disconnecting the
wire and maybe shorting the connector.
The engine should run fine (in fact better) w/o the EGR.
I'm also at diagnosing EGR, just waiting for my roomie to
dig up his vac pump and gauge
Tiv
The proceedure for checking the EGR is posted by me below. You do not need to plug the vac hose for the EGR valve when you remove it. There should be NO vac when at idle. If there is a vac going to the EGR valve at idle, then the DPFE is very likely the culprit.
Good luck guys.
Originally posted by TourDeForce:
The proceedure for checking the EGR is posted by me below. You do not need to plug the vac hose for the EGR valve when you remove it. There should be NO vac when at idle. If there is a vac going to the EGR valve at idle, then the DPFE is very likely the culprit.
Good luck guys.
below? or above? lol.
Gotcha - to be sure I did the troubleshooting correctly, I just came back from Autozone during lunch and picked up a Vacuum Pump from their loaner-tool service.
They have one there for $25.99 but it was plastic and I didn't know how good it was....Probably should have picked it up for that price...but oh well.
I will be testing the EGR later on today when I get home from work.
Thanks!!
The p0402 code is excessive EGR flow. This code is used to signal a stuck open valve (particle lodged on the valve seat or clogged ambient port).
There are 3 parts to the EGR system. You have the Solenoid, the Valve, and the DPFE sensor. The PCM gives a Pulse Width Modulated signal to the Solenoid depending on how much EGR is desired. The solenoid then converts the electronic PWM signal to a vacuum and opens/closes the valve accordingly. At idle and WOT (Wide Open Throttle) no EGR will be requested.
If I were trying to figure this out, I would disconnect the hose off the valve; reset the codes (pull battery connection or appropriate fuses for 15 minutes,); then drive the vehicle with for a while and see if the code sets. The system will not be delivering any EGR flow if the valve is closed.
The system may then throw a p0401 code which is insufficient flow. If it gives the p0402 code I would focus on the valve or ambient port, if it gives a p0401 I would guess that the DPFE sensor is giving a bogus EPTZER reading and needs to be replaced.
One more thing, the strategy may have a two-trip counter embedded it, so you may need to drive the vehicle for a while, shut it off and drive again before any codes will appear.
ok. so I just finished testing the EGR Valve.
I placed a vacuum pump on it, zero vacuum while idling. check
Put 10in of vacuum, car stumbled - did not die, no loss in vacuum. constant stumble. check.
Released vacuum. Gauge went back to 0. Car idled fine.
Car did stumble a bit with no vacuum - gauge did not move when this happened. My mechanic says to replace the DPFE. He says its 98% that its the DPFE Sensor as its a VERY common problem with Fords in general he stated.
Took the DPFE Sensor off - about 20 minutes total time including diagnostics. Not as bad as I thought.
The DPFE Sensor casing is corroded - pieces of it are falling off with my fingers.
Anyway - I'm ordering the DPFE Sensor - What are your thoughts on my findings today with the vacuum gauge.
PS - All vacuum lines seemed fine. I couldn't find any cracks or anything.
Thanks
Do you think its possible to clean the sensor ?
I'd try spraying some intake cleaner - there's nothing to lose.
Tiv
where would I spray it?
it a sealed box - the only thing I could spray is the connectors.....
Originally posted by GR8SVT:
where would I spray it?
it a sealed box - the only thing I could spray is the connectors.....
then into the connectors. it turned out that I've the same
problem (EGR valve works fine). Do you get constant P0402 ?
For me, it kinda comes and goes.
Tiv
well, i only got the code last tuesday. reset the pcm, then the code came back. i drove around for a full day with the cel on....
so that's as constant as I needed it to be.
Well, just to update for search puposes:
I picked up the DPFE Sensor - Part No. F77Z*9J460*AB - from Terry at Sentry Lincoln Auto Group - The black plastic case - Installed it today.
Let it idle after plugging battery back in, idle settled down. Drove it around slow and fast - car drove fine.
Let the car idle for about 10 minutes - idled fine.
Shut car off. Turned back on after a few minutes, drove it around again and again...let it idle. No CEL yet.
FWIW - The DPFE Sensor that was originally in the car - The one with the Aluminum Casing - has a Part No. F48E*9J460*BB
The configuration of the Sensor is a tad different - Both vacuum hoses that connect to the New Sensor - are in front. Where as the old sensor - One is in the rear and the other in the front.
Anyway - Will update if CEL comes back.
Later.
I'm chasing this same problem and thanks to the search I know what I need to do...but damn, I stopped by the dealer today for a DPFE (without the part number in hand) and they wanted $107!!!
Where are you guys getting these things and how much are you paying?
Call Terry at Sentry Lincoln auto group
1-508-995-4600
or Bill Jenkins (I forgot his number....search for his name)
Both will give you a discount if you say your from the Contour group.
I hope my father didn't pay that much at the dealer for the DPFE sensor, but we do get a good discount at the dealer we go to since are there so often.....
but not for one car, when you maintain 5 Ford Vehicles....