2001 Windstar PO401 and PO301

About 6 months ago our 2001 Windstar had a PO401 code - EGR insufficient flow detected. Checked EGR valve for obstruction - negative. Hanes manual showed voltage check procedure for DPFE sensor and they failed, so replaced it and error never came back. Month ago PO301 code - Cyl. 1 misfire detected came up. After reading over this forum decided to take upper intake manifold off and check EGR ports and the fuel injectors. All were fine. Checked EVR for voltage present and coil resistance (according to Hanes manual) and it checked OK. Checked EGR valve, MAF sensor, and DPFE again. Valve and MAF look OK, but DPFE not reading correct voltages (according to Hanes manual) with a warm engine (drove around a country block to warm it up before checking voltage on signal terminal). Voltage reads 1.0 when it should be reading 4-6. Any suggestions, I'm at loss? Thanks.

I am a bit rusty on my DPFE volatage levels but it souinds like you warmed up the van and then checked the EGR flow (via DPFE signal voltage) while tha van was at idle. The EGR valve will not be open at idle. What you may wish to try is to use a vacuum gauge on the EGR vacuum input to open the EGR while at idle. (The engine will run rough and may stall). See if you get a changing voltage vs amount of vacuum applied.

You may also wish to remove the vacuum line to the EGR valve and plug it with a golf tee or someting similar. Go fo a drive and see if the misfire disappears. This will rule out the EGR system (including Ports) as the cause for the misfire. You may get a different code due to the temporarilly non-functioning EGR system.

Thanks for the input, DRW. Not having a vacuum pump on hand I opted first to plug the vacuum line as you suggested (with a golf T) and drove around for a little bit. The van continues to run (and idle) very rough. In fact my son was riding in the back seat just today and wondered why the van was shaking him so much. A week ago I had Auto Zone check the latest error code and it read PO301 and I told them they could reset it. This was a big mistake because now the engine light won't pop back up and signal an error code, so here I am left trying to figure it out or pay a dealership big bucks. I'm stubborn and don't give in easily. Tomorrow I'll see if Auto Zone has a pump I can rent or borrow to give your other suggestion a whirl. Thanks again.

If the fault still exists then the light will eventually return.

You could use human power (IE sucking) to open the EGR valve at idle. Just use a clean piece of rubber hose.

IF ther EGR system was disabled and the van still runs rough then I believe you either have a stuck open EGR valve. (Mechanically stuck open) or your problem is not EGR and EGR port related. It does seem like the EGR codes have disappeared so I would not suspect the EGR system at this point.

It could be a fuel injector or pressure problem or an ignition (spark) problem. These items should flag Codes however. Is the 301 a misfire code?

Yep, PO301 is Cylinder no.1 misfire detected. Already physically looked at the fuel injectors and they're not gummed up in the least. Before I even dismantled the upper intake manifold I put some Lucas brand injector cleaner in the gas tank and some premium gas before that. The two of these might have cleaned up any gummy mess on the injectors, but then why would I still have a rough running engine if it was a plugged up injector in the first place? I'm wondering if I'm not down to the coil pack at this point. I'll have to investigate my Hanes manual to see how to check that out, if there is a way. I just have a hard time believing it's the coil pack. I heard or read somewhere that the cylinders are paired up per coil, so if this is the case more than one cylinder would be misfiring. In relation to the EGR system, it just seems funny that a while ago I had an EGR error code and more recently I now have a misfire. Seems to me like the two could be related. Wouldn't be too hard to swap out the EGR valve, but it may be wasted money. I'll try sucking on the vacuum port to the EGR like you suggested. Thanks for all your advise.

Based on what you say I tend to think the EGR system is okay. The injecter may not be fouled but perhaps there is an electrical issue with the injector. You are correct that the spark plugs fire in pairs but it is still a possibility. Are there any strange mechanical noises?

Keep trying

Based on what you say I tend to think the EGR system is okay. The injecter may not be fouled but perhaps there is an electrical issue with the injector. You are correct that the spark plugs fire in pairs but it is still a possibility. Are there any strange mechanical noises?

Keep trying

The only noise I ever heard was before I took apart the manifold and reassembled it. Before then, at that time the van intermittently hestitated really bad and you could hear popping noises, almost like little backfiring noises while driving. After I took apart the upper intake manifold and looked it over (and the fuels injectors) and then reassembled it, the hestitation and popping noises seem to have gone away, but the engine runs rough consistently now, whether idle or driving.

What did the EGR jets (under the upper intake manifold) look like?

I believe the injectors were redesigned as of '99 (?) to be very clean burning. I have removed mine (150k miles) and found nothing to clean.

What did the EGR jets (under the upper intake manifold) look like?

I believe the injectors were redesigned as of '99 (?) to be very clean burning. I have removed mine (150k miles) and found nothing to clean.

The EGR ports had a coating of carbon on them, but not enough to cause any blockages. The fuel injectors were very clean.

Does anyone think there's potential for the gasket to be bad under the lower intake manifold? I read on someone else's post where someone said it could be suspect, causing coolant from the adjacent water jacket to no. 1 to seep in and cause no. 1 to misfire. I don't relish the thought of stripping down to the block to look at what is only a possiblity. I haven't seen any signs of dampness on the spark plug to no. 1, just evidence that it's not firing like it should.

I replaced my lower gasket, but I don't recommend you do that just yet.

Are you losing any coolant?

Have your cables been changed out?

I replaced my lower gasket, but I don't recommend you do that just yet.

Are you losing any coolant?

Have your cables been changed out?

Good point 12ounce. The coolant level isn't diminishing so that issue is moot in that respect. By "cables" can I assume you mean spark plug? If so, yes they have been replaced with premium along with platinum plugs. On top of that I even went so far as to exchange the new ones at Auto Zone with the possibility that they were bad, so two new sets have been tried out. I also traded the new platinum plug in cylinder one with another new one...to no avail.

I did fail to mention in my past correspondence that when the plugs and wires were originally changed a month ago the cylinder one misfire problem went away. It wasn't until Christmas morning that the problem has reoccured.

Thanks for your input, 12ounce.

1.Trying "listening" to each individual injector. You can use a length of small dia hose. There should be a repetitive clicking heard.

2. As mentioned, the plugs spark in pairs. There are actually only three primary and three secondary coils ... with a plug hooked to each end of each secondary winding. Plugs in Cyl #1 and Cyl #5 "fire" together ... one being a "wasted" spark because its associated piston is not on compression stroke. If there is enough slack in the cables, you could swap the (cyl #1 & cyl #5) cables at the ignition coil pack. If the misfire moves to cyl #5 .....

Another way to check missing sparks is to use a timing light that uses a clamp-on current pick up sensor. Check each cable near the plug to see if all have similar affect on the timing light.

1.Trying "listening" to each individual injector. You can use a length of small dia hose. There should be a repetitive clicking heard.

2. As mentioned, the plugs spark in pairs. There are actually only three primary and three secondary coils ... with a plug hooked to each end of each secondary winding. Plugs in Cyl #1 and Cyl #5 "fire" together ... one being a "wasted" spark because its associated piston is not on compression stroke. If there is enough slack in the cables, you could swap the (cyl #1 & cyl #5) cables at the ignition coil pack. If the misfire moves to cyl #5 .....

Another way to check missing sparks is to use a timing light that uses a clamp-on current pick up sensor. Check each cable near the plug to see if all have similar affect on the timing light.

Thanks 12ounce. I'll try both the hose idea and cable swapping idea.

I had the P0401 code on my 02, and was about to change the EGR when I decided to do some research. There is a service bulletin on the DPFE being a crap part. I took it to Ford told them about they replaced the DPFE and cleared the code at no cost. The van was out of warranty when this happened, but that service bulletin made sure that Ford ate the cost. I can't remember the bulletin number, but I am sure you can find it on the web somewhere. Anyhow not that this is the problem you are dealing with now.

I had the P0401 code on my 02, and was about to change the EGR when I decided to do some research. There is a service bulletin on the DPFE being a crap part. I took it to Ford told them about it they replaced the DPFE and cleared the code at no cost. The van was out of warranty when this happened, but that service bulletin made sure that Ford ate the cost. I can't remember the bulletin number, but I am sure you can find it on the web somewhere. Anyhow not that this is the problem you are dealing with now.

I am hoping that you installed double platinumn plugs. Only Motorcraft and Autolite brands have them. Bosche has been known to not do well in our Windstars.

It is also possible that one of the new spark plug cables is bad.

If you suspect a spark plug.....you can try swapping it with another cylinder's plug.

I had some crud on the spray end of my fuel injectors....that I had to remove the injectors to clean.... It came right off with just a simple squirt of cleaner up inside the "cap" .
If you remove any fuel injectors.....swap the injector for the problem cylinder with another' cylinder.

Another possiblility is that there is an issue with the electrical signal to the injector. One connection is always "hot" when the engine is ON.
The other connection is given an momentary ground by the PCM to give the squirt of fuel.
It is unlikely that the PCM is defective...but a poor connection in the wiring to the injector is a possibility.

As I like cheap and easy solutions.....I would give your next several tanks of gasoline a dose of Chevron Techron Fuel System Cleaner. Your 20 gallon tank will require 2 bottles of "Treats up to 10 gallons". They sell this at Autozone.
I have used some fuel system cleaners that seemed to do nothing. I have used the Techron....and I see it recommended in this forum as being effective.