Engine light - EGR problem

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Jul 1, 2008 | 08:54 PM

2000Expy

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From: VA

Engine light - EGR problem

I had this light once, and took it in to get the code checked. My mechanic diagnosed EGR valve problem, but decided it was more likely the EGR sensor that was bad based on past experience. Well the light went out for a while, and then came back on. Any ideas?

Jul 1, 2008 | 09:36 PM

sbclemens

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What was the code? Any symptoms?

Jul 2, 2008 | 07:40 AM

projectSHO89

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From: St Louis

Did you use a Motorcraft sensor or an after-market one?

The aftermarket ones seem to fail with a high rate.

Steve

Jul 2, 2008 | 09:53 AM

pos2nat

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I used to own a '00 EB 5.4 AWD with a similar problem. There are two rubber vacuum lines from the EGR which get old and cracked causing a vacuum leak which triggers the codes. I can't remember the code but it was either a downstream pressure or upstream pressure code. The only way you will know the line is cracked is to remove them and manually flex them. I replaced both and solved the problem. The cost was about $3.50 for the universal vacuum line.

Jul 2, 2008 | 01:20 PM

a64armt

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I also had an EGR code on my 97 5.4 Expedition caused by a broken vaccum line. The break was behind the battery, against the firewall.

The EGR code is most likely a P401 or P0401

If you are interested in troubleshooting the EGR valve code yourself, see if this helps.

http://home.coastalnow.net/~a64armt...0401/Slide1.JPG

http://home.coastalnow.net/~a64armt...0401/Slide2.JPG

http://home.coastalnow.net/~a64armt...0401/Slide3.JPG

http://home.coastalnow.net/~a64armt...0401/Slide4.JPG

http://home.coastalnow.net/~a64armt...0401/Slide5.JPG

Vincent

Jul 2, 2008 | 04:42 PM

eallanboggs

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Vincent's pictures are very informative, but the Ford DPFE system is pretty complicated so a lot of things can set P0401. In what order should he procede in troubleshooting this fault? Maybe he might try doing the easy and cheap things first. The rubber hoses to the DPFE and the hoses to the EGR Vacc solenoid(stiff and brittle, prone to cracking). Then he can use his DVOM to check all the voltages shown in Vincents photos. Just doing those things will tell a lot and doesn't cost anything. A can of electrical contact cleaner will flush trash out of the DPFE and EGR diaphram both of which have EGR gasses passing through them. Does the EGR vacc solenoid pass the vacuum to the EGR valve so the diaphram allows the EGR gasses to recirculate? If all this doesn't work it's probably time to get the wallet out and replace some parts. If that doesn't work the throttlebody elbow has to come off and get cleaned with at tooth brush. After that there isn't much left.

Jul 5, 2008 | 11:27 AM

Gerdva

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Joined: Dec 2007

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Had the same code some time ago, (checked at Autozone) the code said "insufficient EGR flow" First I changed the EGR valve @ about 50 bucks, reset the code, but after some driving it came on again. I took off tje EGR valve and noticed a lot of carbon deposits in the ducts that go to the throttlebody. So I took it all off cleaned all parts (TB and Air intake) following instructions I found here in this forum. Just do a search with "throttlebody". It's a pretty nasty job, but it's worth it. Car feels much better after clean up