2001 Cougar 2.5L V6 CEL P0401

[decrotty]

CEL P0401 appears. Car has some misfire, most noticeably at 2000 RPM mostly coasting and then very slight acceleration. Replaced the EGR and that is not the problem. Some say the DPFE is the problem. I have the shop manual which shows me a place under the EGR valve. I have no such item on my car. Also saw a discussion on another forum for the 2002 model which has pictures that look just like my shop manual. However, again, cannot find that on my engine.
There is a EGR vacuum regulator on the engine just where the manual says it should be.
Any suggestions? Thanks much.

[Indecline]

EGR would not cause a misfire, unless its stuck open.
you DO have a DPFE and its located under the EGR valve, bolted to the rear bank cylinder head with 2 bolts. Most likely it has the aluminum housing (which absorbs too much heat and causes these to fail)

I found this all easier to do with the induction ducting removed all the way up to the throttle body.

There are two hoses connected to this sensor (HI, and REF) and a 3wire plug. Probe the top wire (Bl/Wh) with a DMM/DVOM and check the Available Voltage with Key On Engine Off, by connecting your black lead to the (-) bat post, and red lead to the needle probing the wire. You should see betwenn 200mv and 1.3v with Key on and no vacuum applied.
IF you DO see that amount, disconnect the front hose from the bottom of the sensor, and connect a rubber hose and suck on it.. pretty hard. (lol) the voltage should increase above 4v.
IF it does not, replace the module, it's defective. (have fun!)
Disconnect your battery cables (ground first) touch them together to clear the EEPROM which stores your MIL light function, and reconnect the bat.

Your MIL light should disappear, and stay disappeared till something else happens. Since it's a FORD expect this soon.



If none of this made sense, simply quit trying DIY mechanics or pre OBDII vehicle. OR simply get a job that pays enough to have somone else do it for you


If you have any questions though, I will try to answer

[decrotty]

Actually the DPFE on my car is NOT where everyone says it is. There are two bolt holes where that metal item should be. I went to a Ford dealer and the parts guy was kind enough to show me a very small plastic item just around the corner from the standard spot. This DPFE is right under an odd cylindrical sensor that is bolted to the intake manifold (that must be removed to get at the smaller DPFE). It is not bolted to anything but has one electrical connection and two short hoses that connect to the EGR tube.
Should note that even Ford's diagrams only show the larger metal type DPFE.
Perhaps my description of the rough running at low RPM as misfire is incorrect but these disturbances are now gone with the new DPFE.
I must assume that for some short time for the 2001 model Ford used this smaller unit.
Thanks for your help.
Actually, while I'm not really great at auto mechanics I really enjoy puzzling through problems like this. My cars are really boring until they reach that age when they start getting interesting like this. In the old days a car with 50,000 miles was old and causing trouble. Today it seems you have to get well above 125,000 before that happens. And yes I can afford to have someone else fix the darn thing and my wife wants me to get rid of this one.

[Indecline]

Yes, do get rid of this car ASAP.
I would get rid of mine, but second gear synchro grinds unless you double clutch.... in other words i need a tranny overhaul/replacement before I'll be able to sell it for what its worth

[Indecline]

This is what the old one looks like.

The new plastic one bolted to the same spot

The cylindrical item you were speaking of... Pretty sure thats the Pressure regulator solenoid... your DPF was below that? interesting. maybe they changed the location for the '01s

[decrotty]

The DPFE is NOT what you show. I think I see the place to insert an image. I'll take a snap of it and post it here later. This one must have been used for a rather short time. However it lasted 160,000 miles.
Actually I really like this car. My curse is that if I find a car I really like they stop making it by the time I'm ready for a new one. The hatch is really nice. Go find a car with a hatch like that today. Not many.

Later,
Attached is a photo of the smaller DPFE. The one tube broke off almost immediately. Perhaps it had a crack and that is what was wrong with it.

[Indecline]

Originally Posted by decrotty

The DPFE is NOT what you show. I think I see the place to insert an image. I'll take a snap of it and post it here later. This one must have been used for a rather short time. However it lasted 160,000 miles.
Actually I really like this car. My curse is that if I find a car I really like they stop making it by the time I'm ready for a new one. The hatch is really nice. Go find a car with a hatch like that today. Not many.

Later,
Attached is a photo of the smaller DPFE. The one tube broke off almost immediately. Perhaps it had a crack and that is what was wrong with it.

Yessir it is. This is off a '99 cougar 2.5L.
this indeed IS the Differential Pressure Feedback Sensor.


**ahem** This Device is a ceramic, capacitive-type pressure transducer that monitors the differential pressure across a metering orifice located in the orifice tube assembly. The DPF sensor receives the signal through two hoses referred to as the downstream pressure hose (REF SIGNAL) and upsteam pressure hose (HI SIGNAL). The HI and REF hose connections are marked on the aluminum differential pressure feedback EGR sensor housing for identification. The DPFE sensor outputs a voltage proportional to the pressure drop across the metering orifice and supplies it to the PCM as EGR flow rate feedback.


nuff said. G'day

[decrotty]

Perhaps they had a few thousand of the older type of DPFE's and put them into some 2001's. Just to keep people guessing. In any case the car runs a LOT better now. Cheers.