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  #1  
Old 06-04-2010, 12:29 PM
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Default P0401

Does anyone know what a P0401 could be caused by?
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Old 06-04-2010, 08:10 PM
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Looking at mazdas dtc chart there is not a P0401 but there is a P0403 which is EGR valve (stepper motor) circuit problem.
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Old 06-11-2010, 07:59 PM
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Is there a code thrown for engine knock?
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Old 06-12-2010, 11:11 AM
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You would think so but there is not, the closest it would get is a misfire code.
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  #5  
Old 06-14-2010, 07:31 PM
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A code P0401 most likely means one or more of the following has happened:

* The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
* There is a blockage in the EGR (tube), most likely carbon buildup
* The EGR valve is faulty
* The EGR valve may not be opening due to a lack of vaccuum
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Old 06-14-2010, 10:35 PM
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replace the egr ~$65 and hope for the best?
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Old 06-18-2010, 06:37 PM
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I've only got 40k miles on it and I have 100k miles of warranty. So I maybe should be ok there. I just have to wait for it to pop up again now that I've cleared it.
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Old 07-03-2010, 05:02 PM
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So they said it is the EGR valve. They are replacing it and all should be well again. I asked what the price would be normally and it is $99 for the part and 1.5 hours in labor. So an EGR valve replacement would normally cost around $330 at the dealer with a bit of a discount for the insurance company. I'm guessing it would be around $350 or so for the average person.

I also had them inspect the cooling system. I regularly get a film on the inside of the windshield and my coolant level drops some. I thought maybe I had a heater core issue. They said the system all looks ok. Apparently, the dash has a chemical in it that off gasses and causes the film. It is a TSB from what she said. And the coolant level dropping is normal. They (Mazda engines) seem to do this and you just top them off.

Yay, now I can put my tune back on the car!
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Last edited by Aubrey; 07-03-2010 at 06:09 PM.
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Old 07-03-2010, 11:45 PM
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i was gonna get that hypertech thing, but then i thought 350+ for 7-10hp....NAH, id buy a used one for 150 tops
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  #10  
Old 07-04-2010, 11:26 AM
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Yeah, if I had to buy it at full price I'm not sure either. Another reason why I haven't gotten a CAI.
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Old 07-04-2010, 11:26 AM
 
 
 
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08, 2008, 626, code, cx7, disable, egr, mazda, mazda3, miata, mpv, p0401, p0403, po401, protege, tribute


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