DPFE and EGR

So I did a search on code P0401. Seems like this happens a lot with these Windstars.

My Windstar is an 2002 with a 3.8L engine. I got the CEL and went to AutoZone and got the P0401 code. Seems like most suggest that it is the DPFE sensor that has gone bad and there is a service bulletin to address this issue.

Well before I go throwing $80 at a new sensor I want to make sure this is the cause. My Ford manual lists a procedure for checking with Key On Engine Running, but I do not have the luxury of a scan tool.

Any suggestions y'all have for possibly fixing this system before I go tossing money into it?

Ie. Suggestions as far as cleaning the EGR itself, putting the vacuum pump on a certain line to check for leaks or just do these things as far as the troubleshooting tree goes?

Basically I need to know before I waste my time what exactly do you clean on the EGR? Should I take the thing off and dunk it in carb cleaner, then blow shop air through it?

I've already taken the DPFE off and looked it over. It looks like it is in decent shape to me, and the wiring and connector look good to. I did try blowing through the DPFE with my lungs to no avail, but assumed this was ok.
Thanks for any and all suggestions.

The DPFE is a common failure. If you have a Haynes there are some measurments one can take assuming you have a multi-meter. If you do not have a Haynes search this forum under DPFE. I actually listed most of the procedure a while back.

EGR Codes are common on Windstars & The DPFE Module is likely. However, It could be the EGR Valve, Vacuum Lines, The Vacuum control valve, or worse yet, the PCM Module/Electrical issues. I would check the EGR Valve by applying a light vacuum to & seeing if it operates (RPM Change) I got a DPFE in the Junk Yard ($8.00) off a Sable ( Many of the Ford 3.0 & 3.8 use the same part.

I had the same code about 2 weeks ago, and I kept erasing the code, but it would always keep coming back, so I went with the suggestion of changing the DPFE sensor, and the code never came back. The sensor only cost me around $60 at CarQuest.

The DPFE sensor senses a difference in pressure between the 2 hose connections......so you would not be able to blow much air through it. There is a slight restriction in the EGR pipe....between the 2 hose connections on it. So.....more EGR flow....the greater the pressure drop across it. The DPFE sensor converts the pressure reading into a voltage, that the PCM reads to determine how much EGR flow there is.....and opens / closes the EGR valve by sending an electrical signal to the EGR vaccum control solonoid.

At idle...there should be very little, if any vaccum in the vaccum line to the EGR valve. The EGR valve should only open under certain drive (car moving) conditions.

One thing that you could do is verify the vaccum lines / connections from the EGR valve, to the EGR vaccum control solonoid.....and to the source of vaccum to the vaccum control solonoid. Look for kinked, melted, hose...and any loose or disconnected connections.

The hose routings for your car may be different than on my '96.....so I will stop there...rather than lead you astray.

The sensor only cost me around $60 at CarQuest.

Well off of the advice of DRW1000 I did plenty of research on it and turns out there is a recall on these DPFEs. I went to Ford and told them about the program number and Service bulletin. I told them I was not going to pay for this and he checked and said yes that the DPFE was under recall. So I got it all done for free in 15 mins. Thanks for all the replies the problem was the DPFE.

Good show!

Always happy to hear that someone got Ford to own up to their design defects.

Thanks for posting the resolution. Perhaps someone else with a relatively new Star will have the proper ammunition to get Ford to fix theirs too.

Have been experiencing the same problems recently. 2002 Windstar, 125,000 miles. Here's the crazy sequence that spanned over 3 weeks: Got a check engine light, Went to Autozone and read the codes, P0402. Replaced the DPFE sensor with one from Carquest $41, engine light didn't go out.

Meanwhile I experienced the Windstar cutting out (sometimes stalling) at low speed like in a parking lot, very infrequent. So a friend told me that is a symptom of a bad EGR valve. Read codes again and got a P0402 and a P1401. Went to Autozone and bought an EGR valve for $48. Replaced the EGR and reinstalled the original DPFE (I wanted to isolate if the EGR or DPFE was the culprit). EGR valve looked corroded inside.

Then check engine light went out for 45 minutes, then came back on again. Read codes again and only had a P0402. Replace the DPFE sensor and tie wrapped it onto the connector because it was semi-loose and didn't clip in. Reset the codes and light hasn't been back on for 30 miles yet. Both DPFE and EGR were replaced. Thanks for everyones input.