1997 Ford Taurus Rough cold idle with a P0402 code

1997 FORD TAURUS
117,000 MILES • 6 CYL • FWD • AUTOMATIC
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JUSTDON
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When the car is first started after sitting overnight, the idle is rough with a "chug" to the engine. If I do not wait until the idle recovers, goes to high idle, and settles in at about 1000 rpms before driving, a code P0402 (EGR Excessive Flow Detected) is set. The code will remain through a certain amount of startups and then clear itself.

Can anyone advise me where to start on finding the cause?
Jul 13, 2009 at 11:30 PM
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MERLIN2021
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Excessive carbon deposit in EGR, holding the valve partially open. Remove and clean/replace EGR. Or defective EGR position sensor, but since it is Chugging, more likely to be EGR.
Jul 14, 2009 at 9:08 AM
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JUSTDON
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Thank you Merlin...

Would the EGR position sensor be the TPS?
Jul 18, 2009 at 6:20 AM
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MERLIN2021
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No Don, it's right on top of the engine, it has the two rubber hoses from the exhaust pipe that connects to the EGR, and an electrical connector. Be careful with these hoses, they tear easily.
Jul 19, 2009 at 6:08 AM
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JUSTDON
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Merlin,

Sorry for the delay on responding. You hit it on the head again. Removed EGR and cleaned it and the ports. Idle is fine with no codes. Thanks a bunch!!
Aug 2, 2009 at 2:32 PM
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MERLIN2021
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Your welcome, Thanks for the feedback!
Aug 3, 2009 at 2:27 AM
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