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4,000 mile trip coming LBZ wierd random miss

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Hey guys so I asked on Facebook and I didn't really get very far so I figured I'd bring it up here. 120,000 mi completely stock.


Here's what's going on.


so with the converter locked and I believe in 5th gear around 1500 RPM I randomly get what feels like a misfire when applying light throttle until the turbo spools up.


I bought this truck from an auction all the glow plugs were bad replaced all those. 


The truck had some dead battery issues right before it went to auction so I looked at the stored codes but ended up clearing them because a lot of them were communication codes which would be related to a dead battery.


All filter replaced, all fluids (except trans and xfer) replaced.


I meant to write down the actual codes but one of them was for EGR and the other ones was for glow plugs.


I've replaced the glow plugs everything is completely fine as far as that goes. the filter head does like to lose a little bit of prime overnight so if I just fire it up first thing in the morning it'll run a bit rough if I put about two pumps onto the primer it runs completely smooth after start.


I have conflicting data from different scan tools some of them are showing the EGR experiencing large error % as far as deviation. My all tell is showing small amount of error (2% at idle) but not enough to trigger a code.


Doesn't feel like 605 torque if I'm honest. Pretty sure my 8.1 could out pull it at this point.



Here are the fuel numbers Screenshot_20220831_172611.thumb.jpg.9fdf15efbc1bd3481c8988ef38ffca16.jpg


Attached is some OBD live data


First few are some screen shots. The one with the date is the most recent.


Here is a link to the EGR doing it thing last week while I drove around town.


Big drive south (AK to AZ) supposed to start tomorrow night. But I don't want it to brake down in the middle of nowhere.


Screenshot_20220821-200138_Autel MaxiAP200.jpg

Screenshot_20220821-203004_Autel MaxiAP200.jpg

Screenshot_20220821-203014_Autel MaxiAP200.jpg

Screenshot_20220822-173046_Autel MaxiAP200.jpg

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   To me it sounds like your having injector problems. I would go ahead and replace the EGR valve to cover that basis. But from your numbers you show on cylinders. #3, #4 are having the issues. Also it seems like your not getting enough fuel boost? Is that correct from your readings?

  Also know that if your still stock on fuel pump, those wear out after alot of miles, to which you have said the truck has. This would explain the lack of fuel boost at the rails. I had my pump go out on my 2016 Duramax. Like you, I got it used. It went out at only 57,000 miles. Apparently GM knew about it, and thier was a recall for unadiquate pumps they were using. But what I learned is that when the pressure from the fuel pump goes out, it also causes the injectors to decline. When my pump went out, it blew all my injectors into the engine. 

  It's also one of those issues where you cannot just replace 1 or 3 injectors, you have to replace all at same time. Before you make that long trip, I would have a shop look at that pump b4 it blows out, and you have what happened to me.. 

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