Windstar 96 - High NOx Emissions

[Zanel]

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
--

[wiswind]

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.

[meta_nerd]

Originally Posted by wiswind

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

[meta_nerd]

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
Upper_Manifold
Throttle_Body

[wiswind]

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.

[meta_nerd]

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?

[DRW1000]

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.

[meta_nerd]

Originally Posted by DRW1000

...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

[DRW1000]

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.

[meta_nerd]

Originally Posted by DRW1000

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.

[ruggratt]

Originally Posted by meta_nerd

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...

[DRW1000]

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.

[wiswind]

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.

[meta_nerd]

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.

[meta_nerd]

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.