1998 Mercury Marquis Check Engine Light

1998 MERCURY MARQUIS
155,000 MILES • V8 • 2WD • AUTOMATIC
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JOSHLIN1932
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  • 4 POSTS
I get a code P0401. The Air Flow system has been cleaned from the air filter to the indake manifold. Replaced the EGR Valve and solenoid. Reset the computer and in about 30 miles the Check Engine Light comes back on. I am at my wits end.

Thanks

John
Aug 24, 2010 at 1:26 PM
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WRENCHTECH
  • CAR REPAIR CONTRIBUTOR
  • 20,761 POSTS
The most common cause of that code is a bad DPFE (Differential Pressure Feedback EGR) sensor sometimes called a pressure transducer.


https://images.2carpros.com/forum/automotive_pictures/561653_DPFE_sensor_1.gif

Aug 24, 2010 at 1:54 PM
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TOMMYG524
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please advise how you, as you say, "reset the computer " in your 98 marquee. thanks so much, tommyg524 aattyyaahhooddottccommm.
Dec 12, 2011 at 2:52 PM
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