2002 Lincoln EGR Low Flow P401

Richard D · **Joined:** Thu Sep 25, 2008 7:43 am **Posts:** 3

I am receiving code P401 on a 2002 Lincoln with a 4.6l. History is: I used fuel system cleaner 44K, after approx. 150 miles of highway driving The missfire code for cylinder #5 missfire appeared, Changed coil pack. Then the random missfire code appeared. Changed fuel filter. All the while code 401 kept appearing.Also installed a K&N airfilter. Have started engine and checked EGR by applying 6" Hg dirrectly to valve and the engine runs rough, re-attached vacuum line from selonoid valve. Checked selonoid valve filter, coil resistance and voltage all correct according to Haynes manual. Any suggestions?

Sponsored Links · **Joined:** 29 Jun 2004 08:12 pm **Posts:** N/A

asecmt · **Posted:** Thu Sep 25, 2008 10:31 am

the engine should almost stall when the egr is opened at idle if is does not then the ports are resricted. if it dies then the dpfe is no good. its a good idea to change the dpfe anyway if the ports are restricted.

Richard D · **Joined:** Thu Sep 25, 2008 7:43 am **Posts:** 3

Thank you, Will let you know the outcome.

asecmt · **Posted:** Fri Sep 26, 2008 8:45 am

let me know if you need to know how to clean them

Richard D · **Joined:** Thu Sep 25, 2008 7:43 am **Posts:** 3

"asecmt" Thank you for you help. I Changed the dpfe. Reset codes and all is well. MPG increased to 31.8. Is it worth cleaning the dpfe or should it just be replaced?

asecmt · **Posted:** Mon Sep 29, 2008 4:29 pm

Glad you got it fixed! No good to clean does not help. I hope you got one from the dealer because the aftermarket ones dont last!

2002 Lincoln EGR Low Flow P401

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