P0401
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P0401
I have a 2002 2wd exp. It just set the ck eng light. scan tool showed P0401, insufficient EGR flow. Does anyone know if there is one thing that causes this most of the time. Is it the diff press sensor, the EGR valve or the regulator. I did a quick ck of the vac hoses and elec connections. all look ok.
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There are several threads on this site about p0401. DPFE IS A POSSIBILITY, but check EGR valve, manually open it and listen to what happens to the engine rpm. If it dies or slows down alot , EGR is ok. check EGR TUBE FLOW and the 2 hoses to the DPFE for blockage. If all is ok and vacuum is good at EGR regulator, replace the DPFE. Good luck and let us know.
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Thanks for the reply. I have ckd egr valve oper. Diaphram is good and you can hear valve move up ad down. I did not operate it with eng at idle though to see if quits or runs rough. I also removed the dpfe and blew our the lines down to the tube. Both appear ok. If you think of anything else let me know. Thanks
Last edited by 12979; Dec 10, 2003 at 10:20 AM.
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I ckd the EGR valve with eng running. Oper is good and passages are open because eng will try to stall when you open the valve. Still trouble shooting. I hope to try and read the dpfe voltage value even though my scanner will not read real time data.
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I blew shop air down both DPFE pick up tubes. [ Up stream and down stream tubes. ] Both are clear. The oriface in the egr tube also appears clear.
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From: North of Salt Lake City
New DPFE sensor available from Ford
There's an upgraded DPFE replacedment part available at Ford dealers is slightly larger than the original. I replaced the old one with a new one and my code has not come back. The new part at the dealer is cheaper too, $29. The part number is: 4U7Z 9J460 AA. Good luck. A very easy (and cheap now) fix. No tools needed.
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