Ranger 2.3L P0401 fix plus bonus PCV replacement | Ford Explorer Forums - Serious Explorations

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Ranger 2.3L P0401 fix plus bonus PCV replacement


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Elite In Memoriam
March 4, 2007
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City, State
anaheim hills,california
Year, Model & Trim Level
95 ranger 4x4/ 91 X 4x4
..As an added feature I decided to include the location and swap of the 2.3L PCV valve and Grommet..:biggthump


..This is on my 95 Ranger and after some reading up on it, I believe this is good for all 2.3L Mazda's/Rangers until the model yr. 2000..I think they added a water jacket to the EGR..:scratch:

..This is copied from one of Aldives posts..This is relative to most all Ford's with the P0401 code..

A code P0401 most likely means one or more of the following has happened:

• The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
• There is a blockage in the EGR (tube), most likely carbon buildup
• The EGR valve is faulty
• The EGR valve may not be opening due to a lack of vaccuum

Possible Solutions

In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.
• Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
• Clean out the EGR valve and/or tubing to remove deposits
• Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
• Replace the DPFE sensor (with a good quality / OEM one)
• Replace the EGR valve

..I've also had this same code when having solenoid purge valve (SPV) and charcoal canister hoses disconnected or cracked so I would also look there too, first..;)

..I checked all the usual places, cleared the code and it immediately came right back..This told me it was a hard fault this time and more than a vacuum leak..:(

..So it was time to get the tools out and go thru the EGR system to try and find the reason for the fault..:hammer:

Warning: Disconnect your battery cables before attempting to repair this..

..This is the location of the 2.3L EGR..It is in the engine bay, behind the motor at the firewall, between your wiper motor and the computer harness..(shown with vacuum line disconnected)

..First thing I had to do was figure out how to get this disconnected as it takes an 1-1/16" wrench to break loose the EGR tube bolts..:scratch:..In this pic you can see where the upper EGR tube nut is located..:rolleyes:

..Due to lack of room I disconnected the lower tube bolt which ties into the tail of the exhaust manifold on the passenger side...Reaching down from the top is the easy and only way to do this unless you plan on removing your starter first..

...I decided to also remove the Idle air Control (IAC) to make the EGR removal a bit easier and I also disconnected the wiper motor for wrenching room..

...This is a picture of the 2.3L DPFE, located with easy access on the passenger side rear of the motor just above the exhaust manifold..These run about $75 dollars and at this time, I don't need one...;)

..This is not your 2.3L DPFE..This is your EGR Vacuum Solenoid and is located on the passenger side just under the rear coil pack behind all the wiring...If you ever need one of these they run about $30..(shown with connector on and both vacuum lines connected. 3rd vacuum line runs elsewhere)


...After disconnecting the lower EGR nut, Disconnecting the 2 hoses from the lower EGR tube to the DPFE, I needed to unbolt the 2 bolts going thru the EGR to the upper intake manifold...They are a #10 head, M8-1.25x30mm..

..This now allowed me to pull the EGR and tube up and out from the back of the motor..Use care when doing this as you have a couple sensor connectors, vacuum hoses, and the computer wiring harness to get by and not cause no damage to them or the tube..:eek:

..This is the EGR and tube pulled..The 2 lines connected rum up to the DPFE..One is 1/4" and the other is 5/16"...These are the original silicone hoses from Ford but they do not carry the same hoses anymore but a cheaper version is in stock..$10 a foot..:thumbdwn:

..Time to do some investigating...Disconnected the EGR form the tube and was surprised to see how clean the tube was..The EGR itself was fairly clean but had hard scale inside..I carefully used a screwdriver to clean the inside of the EGR and flushed it out with MAF cleaner while moving the inerds to watch the operation of the plunger and to make sure it would open and seat properly..

..I did find a couple other items which I don't think had any bearing on the problem...First was the larger of the two silicone hoses had a crack in it...The crack was on the rubber but not thru the silicone core..

Note: Due to the high temp this receives, only use silicone hoses to replace..;)

..Although Ford no longer carries the silicone hoses, You can order some silicone replacement hoses from Autozone at about $12.99 a foot..
Autozone: If new hoses are needed use SU233 for 4mm ID, or SU238 for 5.6mm ID.

..The other problem was with the EGR gasket..It almost looked like it had a thin tin foil coating that got overheated and was flaking all over the place...I replaced it with a NAPA FelPro gasket P/N - 70149 = $2

In Brief

..That's about it...

A) Checked the tube for holes or scaling inside, ran a 12 gauge wire down it and taped it out to make sure it was clean..

B) Cleaned the scale out of the EGR, sprayed with MAF cleaner to flush and verified plunger operation

C) Inspected DPFE hoses and EGR gaskets and replaced as needed..

..Oh yea..I'm not sure if this is proper procedure but this is what I did also so verify before you try it..:D ..While I had the time I pulled the DPFE and spritzed the EGR tubes silicone hose inlets with MAF cleaner to flush them out in case there was any debris..None was found..

..Put it all back together and everything seems fine..Now if I get the code again in the future I know what it ain't...This only would leave the next common resolve of replacing the DPFE..;)

..On a side note, this is also a good time to clean your IAC...:biggthump

...I wasn't having any problems in that dept. but when I took it off I found it had 1/4" thick of caked on dirt on the gasket...I scraped clean and re-used the gasket, spray the inside to flush it out with MAF cleaner and verified it's plunger operation...


..On to the Bonus round...2.3L PCV replacement...:D

..Here are the part numbers I used to replace mine..

Napa PCV valve - P/N - 2-9512 = $8.24

Ford PCV Grommet - P/N - E7AZ6A892A = $5

Just showing the original vs. the new PCV valve..

Locating the 2.3L PCV valve..

..This is looking from the drivers side into the front bay of the upper intake manifold..The big hose shown in the opening (center of opening below the vacuum line) is running down to the PCV valve..

..Looking from the front, if you peer down between your #1 and #2 upper spark plug wires and you squint hard following that large hose (shown upper right of this pic), you will see the PCV valve and grommet directly below the upper #2 spark plug..

..I pulled the upper #2 spark plug boot/stick/thingy to get better access..

(upper #2 spark plug boot/stick/thingy)

..A long pair of needle nose pliers would be better to pull th PCV valve and grommet out but I was able to barely do it with a standard pair of needle nose pliers..(shows another view but with PVC valve and grommet removed)

..Just for reference:

..While talking with a Ford Dealership and trying to find this PCV grommet, I found out that the 3.0L and the 4.0L as well as many other makes/models of Fords share the same PVC grommet but not the 2.3L..

..The 2.3L grommet is a different size and is for only the 2.3L engines..;)

..Quick update:

..This worked for two whole days before the CEL came back on..Due to availability and lack of funds, I wound up getting a new DPFE from AZ.. While they sell elsewhere for $75 and AZ has them for $50, Rockauto also carries 2 different ones..

..Rockauto has them for $62 and $42...