Recurring EGR codes P1404 and P0404?

1999 PONTIAC GRAND PRIX
304,922 MILES • 3.8L • V6 • 2WD • AUTOMATIC
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JR47
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Have two reoccurring codes P1404 and P0404. Leaving work this morning the car hesitated a bit while accelerating and about 30 minutes later the car stalled while driving at a low speed. I replaced the EGR about 2 years ago and the codes have been coming back on and off over the past few months but that's the first time it's ever shut off while driving. It started up just fine after and I was able to drive home but any idea on where to start?
Apr 11, 2023 at 2:46 AM
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STRAILER
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The P1404 and P0404 codes are related to the Exhaust Gas Recirculation (EGR) system in your vehicle. These codes could indicate that there is a problem with the EGR vacuum solenoid or the EGR pressure sensor or you have a clogged passage. I would remove the EGR and clean the passages. Please let us know what happens.


Apr 11, 2023 at 12:02 PM
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JR47
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Removed the EGR and cleaned the passages, there wasn't really any build up at all anywhere but haven't had any symptoms like the other day. Drove for quite some time yesterday and everything seemed fine, and the service engine light hasn't come back on yet.
Apr 12, 2023 at 5:32 AM
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JR47
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The service light came back for the p0404 and the CAT and EVA symbols on my scanner where blinking red if that helps but I did feel a little hesitation again when accelerating.
Apr 12, 2023 at 4:29 PM
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STRAILER
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I would replace the EGR valve even though I know you replace it a couple of years ago. They had problems with this particular valve.
Apr 13, 2023 at 11:20 AM