Engine code help!

[Joe Walsh]

Can anyone suggest our next step in trying to fix our Mom's '95 Mercury Grand Marquis?
Here is what has transpired so far:
(Car has 4.6 SOHC V8 with 109,000 miles)

-> Check engine light came on so we pulled the code:

Engine code P0401
"EGR flow insufficient"

-> We replaced the EGR with a Ford OEM EGR and cleared the code.

-> The car ran for about 80 miles with no problem, then the Check engine light came back on and we pulled the same P0401 code.

Any ideas on what to do now?

[KillJoy]

EGR Delete, and disable the sensor via tuning????

KillJoy

[Zack]

Probably those 2 vacuum thingys that sit by the exhaust manifold on the passenger side.

[larryo340]

There was a TSB or Customer Satisfaction Program (like a recall but has time expiration) for replacement of the DPFE sensor, which when goes bad causes that code. I'll try to find it for you.

[Drock96Marquis]

The DPFE sensor is prone to failure - Common issue on 1995-2002 panthers. The EGR valve itself rarely fails on 2v panthers


The new design is supposed to last longer. Her original DPFE should be the aluminum version, the new one is all plastic.

Here is the part number:
4U7Z-9J460-AA

More info on the TSB and p0401 concerns:
http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Board=11&Number=1135969&Searchpage=1&Main=81998&Words=dpfe+dRock96Marquis&topic=0&Search=true#Post1135969
http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Board=11&Number=955343&Searchpage=1&Main=69971&Words=dpfe+dRock96Marquis&topic=0&Search=true#Post955343
http://www.crownvic.net/ubbthreads/ubbthreads.php?ubb=showflat&Board=11&Number=915140&Searchpage=3&Main=67624&Words=p0401&topic=0&Search=true#Post915140

Also check the two hoses to the DPFE and the connection, as well as cracks in the EGR tube.




Good thing you mentioned it was a 95. On 91/92-95 panthers with the all aluminum intake manifold, the EGR channels are prone to clogging with higher mileage. When this happens, EGR related PCIDs will pop up, P0401 being one of them. At over 100k miles, the EGR channels are likely in need of a good cleaning. This is very common and often overlooked.
http://www.lincolnsonline.com/tech/00015.html

p0401 is normally a 'red flag' for either a faulty DPFE on a 95-02, and/or clogged EGR passages on a 95 ;)

[FordNut]

Yep, I called it the EGR sensor when I got one at NAPA for my F150. Same symptoms you described, same sequence (error said EGR, so I replaced it first and the problem came back after awhile). Over 10k on it since sensor replacement with no more problems.

[SlkMerc]

When I worked in the parts dept for a Ford Dealer, the techs used to call that part the " usual suspect " in regards to the engine light coming on. Apparently, the older design used to allow moisture in and that would corrode the electronics, setting the light off. The new design as aforementioned will take care of the problem once and for all. Dont forget to replace the hoses as well.

[RF Overlord]

^^^what they said^^^

DPFE

[larryo340]

The DPFE sensor is prone to failure - Common issue on 1995-2002 panthers. The EGR valve itself rarely fails on 2v panthers


^^^^^ditto
When I was with FORD to replace an EGR valve on a 4.6 was almost unheard of. They rarely ever god bad, but some outside shops that didn't know better were just replacing parts by code numbers.

[Joe Walsh]

Thanks for the help!

I knew you guys could help with good information!
:up:

A new DPFE is going in this weekend.

[CRUZTAKER]

Check the intake snorkle for gumming. It's likely gunked up as well. My Vic harrassed me for an entire summer with egr issues.

[carfixer]

Simple test:
Apply vacuum to the EGR valve. Engine should run very badly. If it does, probably needs a sensor.

Most likely engine will not change or change very little indicating plugged EGR passages. Very very common for EGR passages to plug up. You will have to remove the upper intake to clean the passage.

[Joe Walsh]

The DPFE sensor is prone to failure - Common issue on 1995-2002 panthers. The EGR valve itself rarely fails on 2v panthers

The new design is supposed to last longer. Her original DPFE should be the aluminum version, the new one is all plastic.

Here is the part number:
4U7Z-9J460-AA

Good thing you mentioned it was a 95. On 91/92-95 panthers with the all aluminum intake manifold, the EGR channels are prone to clogging with higher mileage. When this happens, EGR related PCIDs will pop up, P0401 being one of them. At over 100k miles, the EGR channels are likely in need of a good cleaning. This is very common and often overlooked.


http://www.lincolnsonline.com/tech/00015.html


p0401 is normally a 'red flag' for either a faulty DPFE on a 95-02, and/[B]or
clogged EGR passages on a 95 ;)


^^^^^^^^------You Da' Man!!!!------^^^^^^^^

Replaced DPFE module and cleared the code....60 miles later, it throws the same code...

I checked out the link to the lincolnsonline.com and read about cleaning the EGR passages.
I pulled the intake manifold 'elbow'......and sure enough the channel and all three grooves were totally caked up and clogged with carbon.
Now they're all cleaned up and she runs GREAT!

Thanks again for the info and links!

Joe

BTW: I did try a can of SeaFoam through the EGR valve before pulling the intake manifold elbow and only succeeded in SMOKING out the entire neighborhood!!!
Luckily it was a windy day and the 'fog bank' cleared out quickly!

[Tom Doan]

Time to cook a pig.Tom

[DEFYANT]

Time to cook a pig.Tom

I resent that.

[Dragcity]

Anyone know how often these mysterious DPFE modules fail? I replaced the one in my wife's Sable last year and I am getting the P0401 code again.

EGR is functioning properly. Vacume lines are clear and not cracked. What else can it be?

I am getting sick of working on this Sable. The '65 Thunderbird needs less help than this thing does.

[Joe Walsh]

WOW!
This thread was resurrected!

Unfortunately, in the mean time, the '95 GM has been totalled.
:mad:
I sure don't need to worry about that 'check engine' light anymore.