My GF has a 2001 Taurus SES and we had her check engine light checked at Auto Zone. There was a P0401 Insufficient EGR Flow and P0402 Excessive EGR flow code thrown and a misfire on cylinder 5. My first question is, since it is throwing both an insufficient and an excessive flow, would that lead you to believe it is the DPFE sensor that is bad?

Also, could what is wrong with the EGR system be causing a misfire? The guy at Auto Zone said it could be a possibility, and to definitely look at the EGR first.

Thanks for any help

Since it is giving both codes, you are right with the DPFE sensor. However I do not think it will relate to the P0305. Does the engine actually have a misfire? I would check the ignition system to that cylinder.

It does misfire. It feels jerky usually between 35-45 mph. Once I get on the highway, it doesn't seem to do it much, if at all. I am going to check the spark plug right after work today before we go on our trip. I read that cylinder 5 is front middle, is this correct?

Also, I saw this topic in the Windstar section while searching:
http://www.automotiveforums.com/vbulletin/showthread.php?goto=newpost&t=666619

I noticed he said that a tip he received before was to disconnect the sensor. Would this cause any major problems if done before a long 800+ mile trip? If no other issues besides a different code coming up (as he mentioned) I might do this due to our time constraints today.

Also, where is the DPFE sensor located? Her engine Code is U...which I believe isn't the DOHC version of the engine. However, I thought I saw it in the center of the engine block between the engine and firewall. I read on here that is where it is located on the DOHC version.

In that other thread he says he unplugged it for the TEST. I would fix it before going on an 800 mile trip. Since he says get it from the dealer I can only say Pay alot now , or pay alot MORE later! lol

Here is a picture of the sensor and location.

http://i153.photobucket.com/albums/s214/way2old1/taurusdpfe.gif

U and 2 are the codes for the 12 valve pushrod engine one of them is the designation for the FFV version but it's the same engine.

S is the code for the 24V DOHC Duratec

Mike
:smokin:

Well, I did actually replace the sensor before our trip. I figured it was a quick part to replace, so I did it beforehand. On our trip down, which was a 470 mile trip, the check engine light did not come back on. And there is no bucking/misfiring. It seems, as of right now, the misfire was caused by the faulty sensor. We are leaving Monday to return home. I think the sensor was the cause of the issues.

To top it off, we got 32 mpg on our first half of the trip (all high way miles). So I believe the car is running at peak performance :biggrin:. The second half of the trip included more stop and go on rt 13 through Maryland/Virginia, but we still got a good 26 mpg. I did do a fuel filter, oil change, and air filter replacement the previous weekend. Fuel filter was a definite cause in jump, as the fuel was coming out black :eek:. Air filter was pretty dirty as well.

Congrats, and thanks for the update!

-Rod