Windstar 96 - High NOx Emissions

Hello Everybody:
As I'm a novice to this forum, please welcome myself.
I have trouble figuring out what causes High NOx emission failure with my 96 3.8 Windstar.

It only fails under (15 MPH) test condition:
1. 15 MPH and 1649 RPM: NO = 673 - FAIL, should be 512 MAX
2. 25 MPH and 1351 RPM: NO = 724 - PASS, should be 765 MAX

I have done so far the following: EGR Valve (replaced), EGR Regulator (checked, OK), DPFE Sensor (replaced), all hoses, cleaned batterfly channels in intake manifold, IMRC Actuators (checked, OK).

Engine is NOT overheating and NO trouble codes detected.

If possible, I would appreciate a quick feedback as I have another test schedulled for coming Monday. Thank you.
--
Zanel
--

The most common cause of high Nox emmisions is too high of a temperature during combustion. The emission control system that the auto makers came up with is the EGR system.

The EGR system routes exhaust fumes into the intake stream that in effect lowers the amount of oxygen in the incoming air and lowers combustion temperatures.

It looks like you have checked the obvious:
EGR Valve
DPFE
EGR Controller
and hoses

It could be that you have clogged EGR ports within the intake. I am not too familiar with the 96s but some models have a separate port for each cylinder. They normally start to clog and then cause misfires in the non clogged cylinders. Perhaps yours have clogged all of them.

Can you manually apply a vacuum to the EGR port at idle? If so if there is flow it should stall the engine. If it offers no change then it would appear that the EGR flow is not getting into the engine. If it does run rough then perhaps the command to the EGR controller is non-existant or not getting the the EGR Vacuum controller.

I am not sure but I think an intake leak could also affect NOX numbers.

Let us know.

Thanks for the quick reply.
I forgot to mention that I have cleaned all 6 EGR ports also.
Can you please share a step-by-step procedure as to how manually apply a vacuum to the EGR port at idle?
Thank you.
--
Zanel
--

On your EGR valve should be a thin tube that runs to the controller. When the PCM commands the EGR on (or open) a vacuum is applied to this line causing the EGR valve to open.

I would simply disconnect this hose from the EGR and replace it with another hose. Apply a vacuum to the loose end by using either a vacuum gauge or by sucking on it (Careful sticking your head near the engine) with the engine idling. If this vacuum opens the valve and there is exhaust flow then the car will idle rough and eventually stall.

I would think that a malfunctioning EGR system would flag a code (I can't see how itr would not) so we may be barking up the wrong tree.

Thanks, I will do this procedure this evening and let you know about the outcome tomorrow morning.

Now, I understand sertain conditions must exist in order PCM command EGR controller to open EGR valve, such as: ECT sensor = 113F, TPS is in part throttle and MAF sensor is in its mid range.
What else info PCM gathers to open EGR valve?
Can VSS affect EGR system? The VSS is not working properly, speedo is not stable.
Thanks.
--
Zanel
--

Usually the egr system does not work at this low of rpm range or you would have surging problems. I have not seen this test fail on your type of car but if you build up carbon in the cylinders it will increase your compression ratio and possabley increase the cylinder temperature. To clean the carbon out of the cylinders I would buy some Seafoam and with engine idling pull off a manifold vacuum line and allow the engine to suck the can empty, hopefully by flooding engine with the seafoam. Let it sit for 30 minutes than start it. Be warned if it is carboned up it will have a lot of smoke out the tail pipe when started. It would not hurt to put another can in the gas tank.

Thanks qbic1:
By a manifold vacuum line, are you refering to a plastic/rubber hose line coming to upper intake manifold plenum?

the Seafoam hurting can't hurt..........

I would still do the EGR vacuum check as it is an easy check.

Let us know how you make out.

I have put seafoam into the vaccum line that goes to the top of the upper intake manifold on my '96 3.8L. This is the PCV line...and a number of other things connect to this same line.

The only problem that I had adding anything to that line is that I ALWAYS had a fair amound come out the throttle body into the air intake hose.
This is the easiest place to add the seafoam....but I would add it to another location.
I have, carefully, used the vaccum line that goes to the Power Brake unit.

I have put seafoam into the vaccum line that goes to the top of the upper intake manifold on my '96 3.8L. This is the PCV line...and a number of other things connect to this same line.

The only problem that I had adding anything to that line is that I ALWAYS had a fair amound come out the throttle body into the air intake hose.
This is the easiest place to add the seafoam....but I would add it to another location.
I have, carefully, used the vaccum line that goes to the Power Brake unit.

Did you do this while it was running? None should be able to escape the vacuum of the engine. Any vacuum hose should work but the trick is to suck most of the can in slowly before killing the engine. You do want it to sit in the cylinders to loosen the carbon build up. Also you dont want to pour it in to fast and get it in too much of a liquid form because liquids dont compress. 30 years ago we used to use automatic transmission fluid because it was High detergent but I believe Seafoam works much better.

Thank you all for good advices.
As per DRW1000, I have checked EGR Vacuum by applying a vacuum at upper EGR valve port, the engine stalled immediately, thus it is OK.

I have not done any carbon built-ups cleaning yet, but planning on doing so early next week.

Regarding vacuum intake port location: I have two, one on left-end side of lower intake manifold (a hose attached w/bolt) and second on right-top of upper intake manifold plenum next to throttle body.
Which one would be the best to put Seafoam in?
Thank you.
Zane
--

Thank you all again for good advices.
I have passed the emission tests, NOx is now back to normal as everything else.
My assumption is that it was dirty EGR ports.
--
Zane
--

Which port did you put the seafoam into? I have the same problem and am very nervous, as the last car I worked on was my 72 chevelle, years ago. So any help would be appriciated with these cars that make me shreek at even sparkplug replacement.

thanks

Meta,
Your profile says you have a '96 windstar.
I also have a '96 windstar (3.8L engine).
I have been learning as I go.....as I have started doing much of my own car work over the past year.
I have a subscription to www.alldatadiy.com
I have also used the free repair guide at www.autozone.com

I find it best to have a picture of what I am getting into before I start a project.
As I tackle a new project....I take pictures along the way...and post them at http://community.webshots.com/album/201931518cScpNK

For cleaning the parts of the intake that the fuel gets to.... I use Redline Complete Fuel System Cleaner. 1 bottle will treat the tank of gasoline.
I also use this product in a "maintenance" dose....the bottle has markings on the side that indicate how much to add for each 10 gallons of fuel. This product has a lubricant in it that will help the fuel injectors and valves in the engine.
Another very highly rated fuel system cleaner is Chevron Techron. I put 2 "treats up to 10 gallons" bottles into each tank of fuel.

If your EGR ports in the lower intake manifold have never been cleaned.....they most likely are due.
They are cleaned by removing the upper intake manifold. I do not think that one would be successul in cleaning the EGR ports by using Seafoam or a fuel system cleaner.....
The Seafoam cleaning that is mentioned here is for cleaning carbon deposits from inside the engine....as in valves, pistons, and head. The seafoam will also help to clean the IMR (Intake Manifold Runner), and the other parts of the intake.
The easiest place to add the Seafoam...or other product is through the PCV valve port.....but...as I mentioned....I had some run out the throttle body into the flexible hose that goes to the air filter.....so you would want to remove the hose from the throttle body....and wipe things up when you are finished. That is also a good time to see how clean the throttle body plate is.

Spark plugs....I would take the trouble to get ONLY Motorcraft Double Platinum spark plugs.
You can do a search on spark plugs in this room....and find a lot of discussion on them. I change the rear plugs by driving the front end up on ramps.....let the engine cool......and remove the rear plugs from under the car.

wiswind,
I have read through many of the posts you have helped on and would like to thank you for all of your thourough posts. (Actually everyones are very helpfull, but yours have been very very helpfull to me) ;?)

Here is where I stand right now.
Trying to get this 96 windstar (3.8L engine)(125K miles) to pass smog (CA). :banghead:
Replaced the Mass Air Flow already.

========================
OBDII:
misfire status = complete
fuel status = complete
comprehensive status = complete
catalyst status = complete
heated catalyst status = not available
evaporative status = not available
secondary air status = not available
ac status = not available
oxygen status = complete
oxygen heater status = complete
egr status = complete

DTC reported:
P0171 = system to lean (bank 1)
P0174 = system to lean (bank 4)

MIL status:
the malfunction indicator lamp is commanded on.
============================

Here are my symptoms:
Idles very rough when comming to a stop (and just after).
If exiting an inclined offramp the car will usually stall upon complete stop (i often give it a bit of gas to keep it from stalling but don't know if it is helping)
once it sits for about 10-20 sec, it idles better but seems to have a beat like a bad sparkplug/sp.wire. (I changed the front plugs and will finish changing the rear tomorrow). All the vacuum lines seem to work, the EGR vacuum is weaker than the others at idle, but I believe this is ok. I did hook a vacuum up to it and got it to stall the engine by applying suction, so hopefully that means the valve is working. It also seems that if I turn the wheels almost untill power-stering limit the idle drops very briefly for a moment (not sure if this is related). Luckily I picked up an OBD connector so I can play with this tomorrow at home. Please let me know anything that might help. The front 3 sparkplugs were in great shape, I will post my findings tomorrow on the back 3. Thanks for the quick reply... this site so helpful.

Also If I take off the upper intake, do I have to replace any gaskets?

Chris

Chris,

When taking off upper intake manifold plenum, those 6 butterfly-shaped rubber gaskets should be fine, I don't think you would need to replace them.
Mine were fine even after 256K miles.

On your other issues, I think it is related to air intake passages, clean EGR ports (those 6 butterfly ports in lower intake manifold), and check/clean IAC valve.
--
Zane
--

The vaccum line to the EGR valve should have minimum vaccum at idle.....is not unusual to have a small amount of air......I would spray a little seafoam into the vaccum line to clean and lubricate the EGR vaccum control Solonoid. The EGR vaccum control solonoid is mounted to the back side of the upper intake manifold......toward the driver's side. It has an electrical connection and 2 vaccum lines. One vaccum line is the vaccum source....which is connected to the PCV valve vaccum line. The other vaccum line is the one that goes to the EGR valve. The PCM (Computer) sends an electrical signal....(a wavefore) to open the EGR vaccum control solonoid a certain amount..... The amount is determined by the engine conditions. (PCM asking for a certain amount of EGR flow).....and the feedback from the DPFE (which measures the amount of EGR flow).
I would recommend the seafoam to clean and lubricate the EGR vaccum solonoid....in case it is intermittently sticking.

If your EGR ports in the lower intake manifold have never been cleaned.....they most likely are due.
They are cleaned by removing the upper intake manifold. I do not think that one would be successul in cleaning the EGR ports by using Seafoam or a fuel system cleaner...

Once I get the manifold off, how do I clean them. I have Intake Cleaner and/or Carb Cleaner, do I use this and a rag, or is it more involved?

Couldn't get to the plugs from underneath today, I will do it when I take off the manifold. (fingers crossed)

wiswind , Great pics too. Man I am glad you have done this before...

Thanks,

Chris

I posted some pics on my website.

First is of the intake manifold (are these the EGR ports).
Second is of the upper manifold underside condition.
Last one is of the throttle body condition.


EGR_Ports (http://www.monkeyshltfight.com/public/automotive/upper_manifold/EGR_Ports_01.jpg)
Upper_Manifold (http://www.monkeyshltfight.com/public/automotive/upper_manifold/UpperManifold_UnderSide_01.jpg)
Throttle_Body (http://www.monkeyshltfight.com/public/automotive/upper_manifold/ThrodleBodyDirt_01.jpg)

Yes...those are the EGR ports.
The crud is only right there at the port....down inside the passage to the EGR valve will be fine. You can clean them with a small "pick"...or very small screw driver.....and a vaccum cleaner..... or a rag in the lower intake manifold to catch the crud. Very easy to do at this point.

The "butterfly" that you see in the "other passage" is the IMR (Intake Manifold Runner). Those open at around 2900 RPM and give you an extra boost of power. I think of it as the modern day version of a 4 barrel carborator..... If they are not working....you will get a code telling you of which bank.....and if they are not opening or closing. So....unless you are getting a code for them....they are working just fine.

Well kind of funny,
I cleaned out the ports, put everything back together and it ran fine for about 80miles. Then all of a sudden it stalled again upon exiting the freeway on an inclined offramp. No engine light came on so I quickly took it to get it smogged and it passed....YEEEHAAAAA. Then drove from the smogCheck to pick up my lil-brother from school and while setting in a line of cars for about 5-10 minutes the idle got all choppy and the thing stalled out.

I then drove about another 100 miles, somewhere on the trip the check engine light came on again. It seems better than originally, but it still has the same symptoms. I am lost as to what it could be.

I would think that if it was a plug-wire or the coil it would be more consistent. I am wondering if it could be the DPFE sensor, as it says something about keep upright or ???. If I pull the connector off the DPFE it kills the engine, so it is definately working.

Any Ideas on what might be stalling the car and causing the choppy idle?

Since you mentioned the DPFE..............

The DPFE should not cause the van to stall but if the EGR is open at idle the van would run very roughly. Try removing the vacuum line to the EGR valve and see if it stops the stalling. Plug the loose end of the vacuum hose. Of course the EGR valve could be stuck internally to which this test would be inconclusive. EGR troubles should illuminate the CEL but perhaps it will in the next day or so.

...EGR troubles should illuminate the CEL but perhaps it will in the next day or so.

What is the CEL? sorry I am pretty new to all these terms.


The vacuum to the EGR is very weak at Idle which I believe is correct. And If I add a manual vacuum to the EGR it can stall the car out. So I think the valve it working . The only thing that may be happening is if the valve is sticking open for a few seconds longer than it should, or the vacuum isn't releasing quick enough. Oddly enough by cleaning the ports earlier it totally fixed the problem for a while (80miles or so).

I will try running it without the EGR vacuum line and see if it helps, unless this new information give reason to not try it.

Thanks to all so far for your help, I truley appriciate it.

Chris

CEL - Check engine light.

Can you get the code read? This would be helpful. Keep investigating and posting what you find. As you may know there are a lot of knowledgeable and helpful people on this site and they (we) will help.

Sometimes the seemingly insignificant items cause a light bulb to go off in someone's head so post anything you find. The reson for the CEl is important though.

CEL -
Can you get the code read?

I will get one when my wife gets back with the car. I took one just before the smog check and got this:
P1131 & P1151

but the CEL was not on then.

I will get one when my wife gets back with the car. I took one just before the smog check and got this:
P1131 & P1151

but the CEL was not on then.

your codes mean:

P1131: Lack Of HO2S1 Switches, Lean (Bank 1, Sensor 1)
These codes usually do not indicate a problem with the O2 sensor. Rather, the O2 sensor is correcting rich due to an overly lean air/fuel ratio. Check Base Engine Idle, EGR, Fuel System and Air Induction System. Bank 1 refers to the bank of cylinders containing Cylinder #1.
Sensor 1 refers to the O2 sensor closest to the exhaust manifold.

P1151: Lack Of HO2S1 Switches, Lean (Bank 2, Sensor 1)
These codes usually do not indicate a problem with the O2 sensor. Rather, the O2 sensor is correcting rich due to an overly lean air/fuel ratio. Check Base Engine Idle, EGR, Fuel System and Air Induction System. Bank 2 refers to the bank of cylinders opposite Cylinder #1.
Sensor 1 refers to the O2 sensor closest to the exhaust manifold.

So your van is running very lean for some reason...

Perhaps a leak caused from when you got to the EGR ports. Is it possible you left a vacuum hose off? Or perhaps one fell off 80 miles after your fix.

Most common cause of lean codes is a vaccum leak.
They can be difficult to track down....but double check the hoses as you have been advised.

The '96 windstar is not involved in the TSB regarding isolator bolts...etc....so that is not your problem. The PCV line.....that starts at the TOP of the upper intake manifold....next to the throttle body......and goes back to the rear valve cover.....is very easy to bump loose.....and a number of things tap off of it.
Look on the inside of the elbow that is on top of the intake manifold.....after 9 years......is is quite common for a crack to develop on the inside of that elbow. Also, make sure that the oil dip stick is fully seated.....YES....that would also be a vaccum leak if it is not fully seated.

OK here are the new codes: (the ones above no longer show up)
---------------
P0171
P0174
P1151
---------------
MIL is ON
---------------
I/M monitors:
Catalyst Not Ready
---------------


Thanks, I will check all of the above mentioned vacuum lines.

No Cracks, everything looks good and connected. I will take it for a ride tomorrow without the EGR vacuum line connected and see if it stalls on the offramp.

171/174 indicate lean readings. My guess is still an intake leak somewhere. Since these two codes indicate each bank reading lean it is most likely a leak in the plenum or somewhere common to both banks.

I would still look for a leak or a hose loose somewhere.

Is there anyway that the vacuum may not be regulating quick enough? What would make it do this. Because it really is only bad when you first exit the freeway, then it just idles a bit rough and sometimes almost completely seems gone after about 20 seconds. Now that I think about it, about 2 months ago we had our Idler Pulley cease and our belt ripped off and might have torn something up. I havn't seen any damage but I will give it another look when my wife gets home this-evening. Anythng specific that I may want to check on that left side of the engine.

I also saw in a post that someone had vacuum problems when their power-steering vacuum (valve?) wasnt working properly. I couldn't find anything on the power steering pump, is there supposed to be some kind of vacuum line there?

171/174 indicate lean readings. My guess is still an intake leak somewhere. Since these two codes indicate each bank reading lean it is most likely a leak in the plenum or somewhere common to both banks.

I would still look for a leak or a hose loose somewhere.

OK, I will look it over very thouroughly this evening. Thanks.

(also, what is the plenum? Is it the upper intake manifold?)

Yes- the upper intake.

As far as catalyst mode not set.....it takes a certain number of cycles of the "upstream" oxygen sensors to set them......and then the slower switching sensors after the catalytic converters will set.....those are the "downstream" sensors. In other words....those are the last sensors to set up after your codes have been cleared.......which requires the PCM to "relearn" all the data.
In other words....if you have had the codes reset within the past week or so (as in removing a battery cable).....the PCM has to relearn the data.

There is no connection between the vaccum and the power steering....at least not on my '96.

I can't find any visible cracks or hoses off. I don't seem to have much vac on the PCV, how much vac should there be, I don't even feel it when I place my fingers over the end of the tube.

Now the engine definately sounds like it is misfireing at idle and low speeds (hard to tell at the high speeds). I really think that when I am on a slope it is much worse. If I go up a driveway or a big hill slowly the car just sounds like it is going to stall. I had it stall once going out of the driveway, but on downhills I don't notice it (maybe because the engine pressure).

I think I will take the upper intake off again and see if something is clogging the EGR ports again. This fixed the problem for about a day. With it off I can maybe get a better view of the vac lines back there.

I am lost....

Chris

Also when the car is cold, there is basically no evident problem. As it warms up it gets worse and worse.

OK, got the manifold off today and got a good look back behind at all the hoses. The PCV boot (not sure of the name) was melted through both sides. I will replace it tomorrow. I hope this is it....

Thanks for all your help so far guys...

This site somehow gives me confidence to do this stuff my self, and I really appriciate it.:grinno:

Chris Reid

That would be a spot where air could enter the intake system and it would affect both banks. Good catch.
It can also explain a lot of the symptoms you noticed such as rough low idle. Also when cold the PCM increases the Air/fuel ratio - like a choke would - and perhaps this is why the problem doens't occur at cold.

Keep plugging away.

Yes this site is great. I am glad it gives you confidence. Some here love to help. Especially someone who is willing to go and get their hands dirty. Collectively we have experienced almost all the issues possible. I hope you decide to become a regular after your problem is fixed.

I went to the autoparts store and they said they don't have anything that has a bend in it. They told me to just use a fuel line. Is this going to be OK? It seems that this part I took off is specially made. I am pretty sure I can get to it without too much work, so I will put everything back together and worry about it later. Please let me know your thoughts....

Chris

I would think that a snug fitting fuel line installed withput a kink would be fine.

Just my opinion however.

Put everything back together and I am still getting the same symptoms.
when cold it is ok.
once the temp reaches normal driving temp, there is a misfire in cylinder 2.

I did reset the sensors by first using the OBD meter. Then I tried to just unhook the battery for a few minutes. I was hoping the PCM would reset and everything would be good. But as mentioned above, it is still acting up. I will get an OBD reading when my wife gets home tonight.

Last I checked I was getting errors:
misfire in cyl 2.
too lean in bank 1..?(I think)
manufacture sensor ..(something...???) I will get exact messages tonight.

I am wondering if it could be something with the coil/distributor?

Also maybe the bad running before, messed up the plug in cyl2. I believe that is the center back plug, I will try to get a look at it.

Any more Ideas.

Chris

Did you try driving it with egr hose unplugged?

Cylinder #2 is the center cylinder on the back side of the engine. For the PCV elbow at the top of the upper intake manifold.....I ended up using a elbow that I selected from the "Help" brand of miscelanious items at Autozone. I did read of someone having a electrical connection issue to one of the fuel injectors. The way that the injectors work.....1 side is always "hot".....and the PCM provides the path to ground.....to open the injector. Of course.....the path to ground is momentary.....a pulse for each "squirt".
Would be a real tough problem to verify.....and was for the pro's.

I had a problem with one injector causing misfire.....that was some crud over the spray end of the injector. I did NOT have any "lean" codes however. Took me quite a while.....and lots of parts to finally track it down to the injector. And all it needed was a cleaning. But I was aware of....and looking into the problem before it was serious enough to light the CEL. Once the CEL was lit.....The only code was the misfire on Cylinder #2......as I had already replaced / cleaned all the things that one would replace or clean.......it was a simple find from there.

As stated....a vaccum leak is the most likely cause for a lean code. But it would not likely cause a misfire on 1 cylinder.....unless there is a leak right next to that cylinder.

Did you try driving it with egr hose unplugged?

Yes, it ran worse. It was about a week ago so I don't remember exactly what happened. I do know that I plugged the vac line going to it with a screw and drove to the gas station where I thought that the car was running better with the hose on. So I put it back.

I have also hooked up a vacuum to the EGR while at idle and I can basically stop the engine when doing so. I figure the valve is working Correctly, or am I wrong?

Cylinder #2 is the center cylinder on the back side of the engine....
As stated....a vaccum leak is the most likely cause for a lean code. But it would not likely cause a misfire on 1 cylinder.....unless there is a leak right next to that cylinder.

What is the best way to check for vacuum leaks in the little colored vac lines?
I have tomorrow off, so I am really going to get in there and see if I can figure out the prob. I know I have said this plenty of times, but it is when the engine is hot that it starts acting up , there's gotta be an explanation here. I will do some internet research tonight.

Here are the Engine Codes::

1. P0302 - Cylinder 2 misfire detected
2. P0171 - System too lean (bank 1)
3. P1151 - Manufacurer Contrl. Feul air metering (PENDING)

here is exactly how they are, Misspellings and all...

CR

1. P0302 - Cylinder 2 misfire detected
2. P0171 - System too lean (bank 1)
3. P1151 - Manufacurer Contrl. Feul air metering (PENDING)
CR

DRW1000 -
http://www.automotiveforums.com/vbulletin/showthread.php?t=321337&highlight=P0302
Post 4 & 5
Looks like you have seen this before...

Is this only for the '99' and up ?

Yes the TSB is for 99 - 2003 (or so). I think you have an earlier one. The TSB only addresses the 171/174 codes. Now that I see you only have 171 and not 171/174 -as I thought you had may indicate something else. the 171/174 are lean codes and can be caused by vacuum leaks. The fact that you only have 171 and 1 misfire on one cylinder may indicate a lack of fuel in cylinder 2 - causing a misfire and a lean condition. The fuel air metering is suspicious too.

Basic things..........Did you replace the fuel filter? Perhaps your MAF is faulty. You could have a bad injector.

The acting up at hot could be very important. At warm the air/fuel mixture changes and leans out.

Try temporailly blocking the vacuum to the EGR valve. If there is no change then it rules out the EGR system. - this may set a code.

You could try and clean the MAF. Instructions are listed in here somewhere.

Could also be a bad spark plug or bad coil pack or cable.

......Did you replace the fuel filter?
Perhaps your MAF is faulty.
You could have a bad injector.

...Try temporailly blocking the vacuum to the EGR valve. If there is no change then it rules out the EGR system. - this may set a code.
...Could also be a bad spark plug or bad coil pack or cable.

-- havn't replaced the air or fuel filter in a while.

-- MAF is brand spankin new.

-- I will block the egr on my way to the autoparts store.

-- I am going to check all plugs and wires today.

Thanks,
Chris

egr unplugged didn't change anything.

I am however looking into changing the fuel filter. I see you have to release the pressure. Any tips or links welcome....please.

will also check the plugs right now again.

I am however looking into changing the fuel filter. I see you have to release the pressure. Any tips or links welcome....please.

Found one, thanks wiswind :smile:
http://www.automotiveforums.com/vbulletin/showpost.php?p=3275232&postcount=3

Things seem to be a little better.

============== As of yesterday ================
new air filter
new fuel filter
sparkplugs all look good.
Cleaned out the EGR's again, this time all the way inside.
Reset Codes...
============================================

Once engine is hot, I still got the same smptoms. (seem a bit less intense)
choppy Idle, occasional misfire (at first then constant). No CEL untill I get on an incline(once at driving temp for a few minutes). Then it flashes too.

On Inclines I get the misfiring and the CEL flashes. Even if I just pull into my drivway (not steep at all).

Last night I parked it so it would misfire and I turned off all the lights and opened the hood and I didn't see any trace of arcs from the wires or coil. I also checked Cyl 2 wire, looks fine.

I am wondering if there is anything behind the engine that I may have knocked off the first time I cleaned the egr's. I can't see back there so I was wondering if any more-experienced people know of anything that may cause my problems back there.

How would I check the injectors to see if they are a problem? I heard replacing them is tough, but is it possible with just sockets/pliers/wrenches (jackhammer :evillol: ). I would like to do it myself, even if it is difficult -- as long as I don't have to pull the engine and buy a $billion in special tools.

What about this DPFE sensor?
Could the PCV valve be malfunctioning?
How would I check these items for problems???
(I did find that if I unhook the sensor on the DPFE - the van dies, hopefully this means it is working?)

Chris
.

One more interesting thing I noticed tonight.

I had a drive tonight that was about 35 miles each way. I started the car from a cool evening, ran fine (usually does when the engine is cold).

Drove 35 miles no problems. As soon as I come to a complete stop the engine boggs a little and it instantly starts misfiring and the CEL starts blinking. It has something to do with the complete stop, because I slowed down to about 5mph before this and nothing happened.

So I wanted to test this more...
On the way home the exact same thing (started car cold), except one exit away I slammed on my brakes to see if it was the decelleration and it wasn't.
Then I exited the freeway and came to an almost complete stop (barely moving probably 1-2mph) and nothing bad. Stopped at the next light and sure enough it started as soon as I completed the stop. The engine basically goes from an idle of about 700-1000rpm to about 400rpm (not exact but close) then starts misfiring only when I completely stop.

I drove a bit like this trying to accelerate & brake hard anything to change it back to normal and nothing happened. Then about 2 blocks from home I stopped and turned off the engine & ignition. Restarted and it was fine.... drove home with no problems. Once home I read the codes and got the same 3 as the last read (see previous posts)

What the #@!* is going on. Any Ideas what might be causing this?
The only things I havn't changed are the DPFE and the injectors...I think. Hopefully this will shed a new clue for my horrible riddle.

Chris

Have you looked at cleaningh the IAC? It couldn't hurt. The IAC affects idle. How is the MAF? It could be dirty as well.

I don't know what disconnecting the harness on the DPFE should do but if you disconnect the vacuum to the EGR it should not stall. Have you considered that your EGR may be stuck open?

Of course these should be CEL items but I thought I would mention them in any event.

Have you looked at cleaningh the IAC? It couldn't hurt. The IAC affects idle. How is the MAF? It could be dirty as well.


I will look into the IAC.

The MAF is brand new, It was the first thing I replaced. I don't mind cleaning it. I will try anything at this point.

I don't know what disconnecting the harness on the DPFE should do but if you disconnect the vacuum to the EGR it should not stall. Have you considered that your EGR may be stuck open?


I didn't think about it being stuck open (open being when there is vacuum). Is this fix-able or do I just replace it?
The stalling hasn't happened in a while but the idle definatly drops like its going to, and it now gets that misfire in cylinder 2. Is this a symptom of EGR valve.

Thanks DRW1000 I really appriciate all of your great tips...

Misfires could be EGR related. Usually when all of the exhaust is routed to one or 2 ports due to the remainder being clogged. The EGR will stall out the van if it is open at idle. It COULD cause #2 to misfire first.

I am glad to help. I just wish we were having more luck pinpointing it.

Misfires could be EGR related...

I cleaned all the egr ports very thouroughly (twice too). Today I wanted to see if the sticking valve was a possibility.

Here are my thoughts, please correct them if I am wrong.

I figure it must be closed at idle because it works when everything is cold, and if I manually add vacuum then I can stall the car. I also figure if it is sticking, it must be sticking open, because then at Idle it stalls the car.
So I disconnected the EGR vacuum line while the car was cold. This should not allow the valve to ever stick open because it will never get any vacuum to it.
Well once the car got to its running temperature it started misfiring again. So this would kind of eliminate it from being stuck-open EGR. But there are the electrical connectors into the EGR. Don't know if these can cause these problems.

One thing to note:
When I returned home from a 5mile missfiring ride this afternoon I hooked up the OBD and I got:
Missfire in Cyl 2,
Lean Condition ... all like previous posts.
But then I got, P0401 EGR ...??...???. (i think it said not reading correctly, but I don't remember exactly). Anyways I have a feeling the electrical is probably fine too if I don't get this when the EGR vac-line is ON. ???

I didn't get a chance to look up the IAC yet. Maybe I will be able to check this out in the moring.

Finally some progress....

I removed the IAC and it was filthy so I cleaned it as suggested on other posts I found.

I then drove the car until it was hot and came to a complete stop... no idle problem. Did it about 5-6 times and finally the Idle and misfires started up. Then to even make things better... as soon as I got back on the freeway, the misfires stopped (they used to stay constant). Then the next time I exited the freeway, it took a good 6-7 serious stops until the misfires started up again. (this is progress, something new)

I don't know if I ever mentioned it, but when I come to a complete stop the engine does a noticable single shake, and that is when the idle drops and the misfires start happening. The shake may just be the first missfire shifting the engine block???

It also only does this when the car is in Drive or Reverse. When I put it into park the problems stopped. (this is new also, I am quite sure that the misfires happened in park before).

Question:
What is the black knob on the IAC for? I hope it is not an adjustment becuase it did get turned while cleaning and removal.

one step closer.... thanks...

have you checked fuel pressure