Hello-

I just found this forum when I was searching for a problem I am having. <O

I have approximately 125k miles on my 2002 Ford Explorer XLT V6 4.0L(aprox since the odometer stopped displaying long ago…) I will be trying the fix I found on this website!
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My most pressing issue is I need to get the car smogged. The Service Engine Soon light is on and the mechanic I took it too said that I had a bad DPFE Sensor (part # 4U7Z-9J460AA) sensor. He replaced the sensor, reset the light, and told me to drive the vehicle around for a couple days before I get it smogged. On the receipt it said it was code # PO401.
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About 10 or 15 miles of driving around the light back on. I bought a code reader and its coming back with the same P0401 code. After the PO401 code it says: Gas Recirculation: Insufficient flow Detected.
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Question: Is there some check that I can do myself before taking it back to the mechanic? I would prefer to fix it myself to save a little money and hopefully learn a little about my explorer.
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Lastly – Does anybody know a good mechanic/transmission shop in San Jose area? The transmission OD light on my car is blinking and I don’t think I can do transmission repairs myself… The transmission has always given me problems. The current issue is that when I have to brake hard it almost feels like the transmission disengages. After the hard break I will give the vehicle gas and the engines revs but goes nowhere… After a second or two it will then slam into 1<SUP>st</SUP> gear. It also shifts rough into 2<SUP>nd</SUP>/3<SUP>rd</SUP> gear…
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Thanks.
-Eric

 

Welcome to the forum!

The DPFE is a pretty common part to fail, so common that many technicians probably fail to confirm the passages for the EGR are not plugged. You could verify that the two hoses on the new DPFE are not reversed - they should be two slightly different sizes. Some folks have found these to get reversed during replacement. You also could use some STP throttle body cleaner to spray out the passages and make sure they are not restricted.

Other than changing out the transmission fluid and filter, which hopefully has been done at least a couple of times in the vehicle's life, I have nothing to offer on the transmission issue.

-Rod

 

Thanks Rod,

As you recommended the problem looks like it was one of the hoses not being correctly connected correctly and so far the light has stayed off. I'm going to drive it around a couple days to make sure it doesn't come back on and then take it to get smogged.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
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As for the transmission. The problem actually started to get more severe after the dealer did a transmission flush. The code for the transmission is coming back with a bad solenoid. I'm just worried that I've waited to long with the OD light flashing that I may have caused initial damage to the transmission... Hopefully, I can find a reputable transmission shop that can repair/rebuild/replace the transmission.


Thanks again for your help.
--Eric

 

It's unlikely the hoses are reversed. Ford tried to Murphy proof them by making them different sizes. If you try anyway you would have to force one on and the other would fall off by itself because it would be too big to fit tight. The ECM energizes a solenoid that provides vacuum to the EGR valve allowing flow while the DPFE sits there waiting to see if the commanded flow takes place. The DPFE tells the ECM if everyone is following instructions. The DPFE monitors everyone else, but no one monitors the DPFE. If you get P0401(Insufficient Flow) it doesn't mean your DPFE is defective. If means your DPFE is reporting to the ECM that there is insufficient flow. That's what the DPFE is supposed to do if the flow really is insufficient. The DPFE could also report that flow is good if it is good. You can also have the ports in the throttlebody elbow between the EGR valve and the intake manifold clogged with tar from your exhaust. The will cause insufficient flow which the DPFE will correctly report to the ECM. Some mechanics are parts changers. Don't be a parts changer. You will just be throwing away money.
Your trans sounds like it is shot. You could try the old shadetree mechanic trick of adding sawdust to your trans fluid and sell the vehicle to your brother in law before he figures out what you did.

 

My old 95' explorer had the same problem, OD light blinking on and off and hard shifting, It was the Plastic gear got it from Ford ($27) that mounts to the top of speed sensor that fits in to the top of transfer case on 4wd models, and fits into top or side of transmission of 2 wd models. This solved it completely. I have a 02' Explorer but I don't know if they have same or similar sensor with the gear, I would think it would be similar.

 

saw dust??????? how about the valve body- shifting.

https://www.ford-trucks.com/forums/588191-5r55.html