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Engine stumbles at a stop

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Old August 9th, 2023, 3:54 PM
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O2 sensor voltage looks a little funky. Can you graph it?
Old August 9th, 2023, 4:50 PM
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Originally Posted by mountainmanjoe
O2 sensor voltage looks a little funky. Can you graph it?
Yes sir, I will and get back with you on this post.
Old August 9th, 2023, 6:02 PM
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I'm just a shade tree mechanic too...
O2 stuck out to me but RPM looks a bit low too. I also don't ever remember seeing exactly 0 for throttle position. Might want to graph that too while moving the throttle. Does it show the idle air control?

Edit: according to this I'm wrong on the RPM.
https://www.tahoeyukonforum.com/thre...dle-rpm.29465/

Last edited by Triaged; August 9th, 2023 at 6:07 PM.
Old August 9th, 2023, 6:03 PM
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I should add... Your temps look fine.
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Old August 9th, 2023, 8:07 PM
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Which o2 sensor are you referring to. I replaced the bank 1 sensor 1 with oem.
Old August 9th, 2023, 8:53 PM
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Bank 2 sensor 1 is what I saw. For driveability just the first sensor matters. The second is for emissions.
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Old August 9th, 2023, 9:58 PM
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sensor 1. Both banks
Old August 9th, 2023, 10:02 PM
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I just replaced the bank1 sensor 1 with a new AC Delco oem.
Old August 9th, 2023, 10:23 PM
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Ya'll got to remember now.I was sitting still on all if these screenshots. That's when I'm having the problem. Sitting at a light or stop sign. Otherwise it will run just fine
Old August 10th, 2023, 3:09 PM
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Originally Posted by outtactrl
I just replaced the bank1 sensor 1 with a new AC Delco oem.
I know. You already said that. Maybe the sensor isn't the problem. Maybe the wiring is damaged or there's an exhaust leak. Who knows.
It still would helpful to see the graphs. Something doesn't look right to me.
We are diagnosing here, right? Not firing the parts gun and hoping for the best.

Last edited by mountainmanjoe; August 10th, 2023 at 3:11 PM.
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