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1996 gmc jimmy 4.3 vortec misfire

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Old Oct 17, 2018 | 10:08 AM
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Default 1996 gmc jimmy 4.3 vortec misfire
New plugs wires and cap and rotor cat is gutted out to. It has a misfire between 2-3k rpm under a load. If I down shift to second and drive at 3000-3500 rpm the sputtering gets worse and gets to where it’s pops out the exhaust. Codes I’m getting are p0420 and p1441
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Old Oct 17, 2018 | 10:45 AM
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How were the old plugs?
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Old Oct 17, 2018 | 11:43 AM
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Originally Posted by geo1
How were the old plugs?
they looked normal to me light brown ish kinda color
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Old Oct 17, 2018 | 2:38 PM
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The "popping out exhaust"makes me think , ignition module,did that and 1441 show up at same time?
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Old Oct 17, 2018 | 2:49 PM
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Originally Posted by geo1
The "popping out exhaust"makes me think , ignition module,did that and 1441 show up at same time?
1441 came on yesterday its been acting up for quite awhile it’s been parked for about a month been driving it all week I’m waiting for it to give me a misfire code or something I can get some info off of
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Old Oct 17, 2018 | 3:43 PM
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Have you cleaned the MAF?and how old is fuel filter, trying to think of,what's making a lean condition,you could also unplug cts,make it go rich,see if drivability improves
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Old Oct 17, 2018 | 7:45 PM
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Originally Posted by geo1
Have you cleaned the MAF?and how old is fuel filter, trying to think of,what's making a lean condition,you could also unplug cts,make it go rich,see if drivability improves
cleaned maf late last year and fuel pump and filter were done in 2015
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Old Oct 17, 2018 | 8:52 PM
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Change the filter,going on 4 years,and I would disconnect cts for a test drive
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Old Oct 18, 2018 | 11:44 AM
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Originally Posted by geo1
Change the filter,going on 4 years,and I would disconnect cts for a test drive
new update it’s misfiring pretty bad still but it seems like only in the mornings in the afternoon it’s fine. Also when it’s missing out it will kick out or overdrive going down the road
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Old Oct 18, 2018 | 11:57 AM
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What grade plug wires did you install?sounds like you have stray spark,I would use a spray bottle with water in it,slowly spray plug wires when it's behaving,try to get it to misfire,or take a peak under hood with limited light,look for arcing at plug wires
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