98 jimmy, trouble code PO404, replaced EGR, still not fixed

1998 GMC JIMMY
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SGGRIFFEY
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98 jimmy, 4wd, bucks and jumps, just started doing it, not gradual. Nothing changed after replacing EGR valve.
Any other ideas???
Sep 18, 2007 at 3:06 PM
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MERLIN2021
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I'll see if I can help, now what engine and Jimmy are we dealin with? S or K?
Sep 18, 2007 at 3:43 PM
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SGGRIFFEY
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[quote:9b57888be4="merlin2021"]I'll see if I can help, now what engine and Jimmy are we dealin with? S or K?[/quote:9b57888be4]


just got a reply from another site. i was told the catalytic was possibly melted together causing back pressure. i removed the O2 sensors in front of the catalytic and it drove great (just loud). i'm on my way to replace the catalytic converter right now!
thanks!!
Sep 18, 2007 at 4:15 PM
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MERLIN2021
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  • ASE Certified Mechanic
Have a nice day!, but any codes? we don't want to wreck another converter do we? This will happen when the check engine light is flashing...
Sep 18, 2007 at 6:00 PM
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