how to fix engine code po400

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Feb 25, 2003 | 05:52 PM

red96z

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Joined: Jul 2001

Posts: 626

From: memphis tennessee usa

how to fix engine code po400

does this mean i need new egr?

Feb 25, 2003 | 06:15 PM

drop top steve

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Joined: Aug 2000

Posts: 504

From: Portland, OR

Go to your local Chevy dealer and ask if you qualify for "special policy #00096, egr replacement" if your under 70,000 miles you should be.

Feb 25, 2003 | 06:21 PM

shoebox

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Joined: Dec 1969

Posts: 27,725

From: Little Rock, AR

It means the pcm is not seeing enough change in MAP when the EGR is energized or de-energized. It could be the EGR valve is sticking or the vacuum diaphragm is not holding vacuum, bad vacuum line/leak...

Feb 26, 2003 | 09:15 AM

EviLBoX

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Joined: Dec 1999

Posts: 825

From: Houston, TX

Cleaning the EGR or replacing it may fix the problem, but if not you're another victim of the "lack of enough backpressure to make the EGR function properly" in which the only real fix is to have the code programmed out. I've recently seen a post where someone made an EGR simulator though, but I haven't tried it. Do a search for "P0400" in this forum for more info.