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

[sggriffey]

98 Jimmy, 150,000k, 4wd, no problems until it started bucking.
Replaced EGR but nothing changed.
What is next to try? (just sold it to my son!!!)

[96_blazer_5spd]

i had this problem a while back, if you are also having a bad loss of power, check to see if your exhaust is plugged, the insides of my catalytic melted together

[sggriffey]

Originally Posted by 96_blazer_5spd

i had this problem a while back, if you are also having a bad loss of power, check to see if your exhaust is plugged, the insides of my catalytic melted together

checked with my muffler guy. he had me pull the O2 sensor out to see it the pressure would be relieved in front of the catalytic. it worked! the jimmy ran great (just loud). on my way to replace the catalytic converter. GREAT HELP!! THANKS!!

[old_master]

A melted catalyst is the result of another problem. Converters don't melt by themselves. That is the symptom, find the cause or you'll be repairing the symptom again. Find out what's causing the rich condition. Possibly a missfire caused by a secondary ignition problem, or possibly a leaking fuel injector or leaking fuel pressure regulator.