1997 4.6 EGR insuffecient flow

absaluteviktory · #1 10-26-2009, 12:40 AM

97 F-150 code 90401 I think it is...EGR insufficient flow. I have test the EVR for continuity,it was in range, tested EVR for voltage, it was 14.05v with key on. Tested DPFE valve for voltage with engine cold, it was high, out of range at 2.45v.....could it be the DPFE or could something else cause the code for insufficient flow to EGR? I have already replaced the EGR itself. Also when I checked my water in radiator, it was a pint low. I know it was full a week ago because I had flushed and filled the system for winter, and run the truck and rechecked the level after it was cool.

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Patman03SprCrw · #2 10-26-2009, 12:49 AM

check for air flow through the intake manifold from the EGR valve to the back of the Throttle

venom65 · #3 10-26-2009, 11:55 AM

This apparently is a fairly common problem with the DPFE sensor. I had the same issue come up on my truck and when I spoke with the Muffler shop they said it was normally the DPFE switch. I replaced the sensor and all is fine now. The job took all of 10 minutes. No more DTCs or MIL.
Watch out for the fact, that when you order the part, make sure you take the VIN number and the emmissions calibration number listed on the drivers door jam. They have a couple of these sensors, so make sure you get the right one.
Happy motoring.
Bob
Venom65

sagittarius1 · #4 10-26-2009, 02:41 PM

Have you every cleaned the throttlebody - intake spacer yet?

I had the same code, 1999 4.6 with 150k miles. Where the EGR vents into the throttle body spacer, the two holes were almost completely plugged.

I bought 4 new gaskets for about $25, EGR, Throttle body, Throttle body spacer, and IAC gaskets. Pulled every thing apart, cleaned every port/hole with B12 intake cleaner, put back together ...... no more "EGR insufficient flow" code.

If you have not done this cleaning yet, you are over due. It is cheaper possible fix than a DPFE sensor, and may be needed anyway.

Matts ford · #5 10-26-2009, 03:26 PM

sagittarius1- are you talking about the 90* elbow that comes up from the intake and the tb bolts to it? because these truck dont come with tb spacers.

if you need a dpfe then get motorcaft only, along with the hoses. and you need to suck test the egr to check if the ports are plugged or not.

venom65 · #6 10-26-2009, 04:28 PM

Agreed, Matts Ford is right. You need the genuine Ford part. My dealer had both the versions in stock and I picked them up and finished the job in record time. There is not much flow through the hoses but they can crack over time causing leaks. It is sort of funny but when I pulled mine off and looked at them they were fine. I then got worried becasue I took both off at the same time and hoped I got them back right until I realized they can only go on one way. The ports are different sizes and the hoses only fit on them one way.
Enjoy
Bob

sagittarius1 · #7 10-27-2009, 03:00 PM

Quote:

Originally Posted by Matts ford

sagittarius1- are you talking about the 90* elbow that comes up from the intake and the tb bolts to it? because these truck dont come with tb spacers.

Yes ... the 90 degree elbow (housing, spacer, interface, what ever) between the throttle body and intake manifold.

This thread has a good picture of the plugged EGR ports ...

P0401