'95 Engine Code P1407

[Paul Scanzillo]

Autozone read my codes and gave me a P1407. Their hand-held unit displayed a "manufacturers auxiliary emissions control". The computer in the store displayed a "EGR no flow detected" for the P1407. Wondering if the EGR can be cleaned or should it be replaced? Is there a sensor associated with this code that might be bad? Any help would be appreciated. The van is only doing 16 MPG at the moment, so there appears to be a fuel issue...over fueling the engine as a result of a bad EGR valve? Help!!

Paul Scanzillo

[wiswind]

I have looked in Alldatadiy and do not find that code for my '96 windstar.
So you may want to look into that some more.

Your '95 uses a different intake manifold from any of the other windstars.
The EGR gasses flow through a metal pipe from the front exhaust manifold to the EGR valve.
There is a slight restriction in the pipe, and there are 2 hoses that come off that pipe.
1 hose is before the restriction and the other hose is after the restriction.
The hoses go to a small "box" with an electrical connection on it.
This is the Differential Pressure Feedback (DPFE).
When there is no EGR gas flow, there will be no difference in the pressure at each hose.
When there is any EGR flow, there will be a difference in pressure between the 2 hoses. The more EGR flow, the greater the pressure difference.
The DPFE converts this pressure difference into an electrical signal that the PCM uses to determine how much EGR gas flow that there is.
The PCM sends a signal to the EGR Vaccum Regulator Solenoid which then opens / closes a valve in the Vaccum line that goes to the EGR valve.

Now, the most common failures would be the DPFE and the EGR port(s) in the lower intake manifold. I do not know how they are set up on the '95, but I can still see where they could become clogged, whether it is 1 port or a port for each cylinder as the post '95 windstar is.
The other common failure is the DPFE, which is a matter of getting a new one and replacing it.

Another thing (cheap) to look at first, would be to follow that vaccum line for the EGR valve, and make certain that it is connected and intact.

[Paul Scanzillo]

Thanks for your help. I've located all the parts you mentioned. I traced the green vacuum line from the EGR down to the EGR Vacuum Regulator Solenoid. It looks like this is the solenoid that the PCM signals to open to allow vacuum to the EGR? The Solenoid has the green vacuum line and a red vacuum line connected to it. I plugged the end of the green (EGR) line and blew into the other end...no leaks.

Is there a way to check for a bad EGR vacuum regulator solenoid or do these generally not present a problem?

I suppose the next step is to replace the DPFE and see if this corrects the problem or try cleaning the ports first?

Thanks again!

[wiswind]

I have not read about the solenoid being a high failure item.
I read a post about the little filter inside becoming clogged, and cleaning it cleared the person's problem. The filter is under the cap on the solenoid.
I doublt that this is your problem...as it has only been mentioned once or twice....so is a rare problem.
The DPFE is a very common failure.....as is clogged EGR port(s).

[CoachKarl]

Wiswind is correct. DFPE. On my 95, 3.8 this gizmo is 1" by 3" by 1/2" and has two rubber tubes of slightly different diameter hanging off the bottom of it, and three wire harness connection facing toward the battery side of the car. I fixed my 1407 issue by replacing the rubber hoses. One had completely deteriorated, and one was full of a white powder. I used drill bits by hand to clean out the ports into the dfpe switch. New dfpe's are about twenty bucks.

Karl

[Paul Scanzillo]

I'm gonna look at the two rubber hoses and see if they are plugged before buying the DFPE...thanks for the tip.

Another question...it's my understanding that the EGR system recirculates some of the exhaust gases back into the intake where they are burned again, in effect, lowering the exhaust emissions. This is accomplished by the DFPE sensing a differential pressure relative to the reference pressure and feeding this info to the PCM. The PCM then sends an output to the EGR regulator, where the regulator opens/closes the vaccum circuit to the EGR valve...thus allowing the regulated exhaust gases to feed back through the intake to be burned again. Here's my question...does a "bad" EGR system affect gas mileage (fuel mixture) in anyway? If so, how? I've noticed a decrease in gas mileage which might be coincidental?? I live in rural PA where emissions are not an issue. We have state inspection annually, but emissions are not tested...YET!!

[wiswind]

The EGR system not working correctly seems to change not only the emissions, but the upper engine temperature, and overall engine performance.
As the engine is very tightly computer controlled, a malfunctioning system will most likely decrease the fuel economy and engine performance.
At least, I have read these 2 things (temp & emisions) enought times from reliable sources to believe that it is true.

As you are doing the work yourself, it is not an expensive repair, so well worth the time and money to fix it.