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Discussion Starter · #1 ·
So I'm having an issue with my 03 LB7, truck is bone stock except for a K&N intake and 4" exhaust. I bought the truck last September and it's always been sluggish and puffed black smoke. I recently changed out the CP3 and the engine harness that the previous owner had hacked to pieces and the truck came back to life with tons of power and no smoke whatsoever. 3 days later I was getting ready to leave a red light and my check engine light came on tons of black smoke and absolutely no power, I put my foot to the floor and was only doing 5mpr. Got the truck back home and put my scanner on it And my balance rates were pegged at 15+/- for cylinders 2 4 6 and 8, cylinders 1 3 5 and 7 were all sitting at 7+/-. I turned the truck off and restarted it and my balance rates were back to normal between 1-2 +/- on each cylinder and was running beautifully again. The next day I started the truck everything ran smooth, idles beautifully But as soon as I hit the accelerator it bogs down and starts acting like there is a miss but as soon as I turned the truck off and restart it everything goes back to normal.. Does anybody have any idea what might be going on here.. Also The truck has 200000 miles on it Lois told the injectors were replaced at a 175000 with boch remans
 

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So I'm having an issue with my 03 LB7, truck is bone stock except for a K&N intake and 4" exhaust. I bought the truck last September and it's always been sluggish and puffed black smoke. I recently changed out the CP3 and the engine harness that the previous owner had hacked to pieces and the truck came back to life with tons of power and no smoke whatsoever. 3 days later I was getting ready to leave a red light and my check engine light came on tons of black smoke and absolutely no power, I put my foot to the floor and was only doing 5mpr. Got the truck back home and put my scanner on it And my balance rates were pegged at 15+/- for cylinders 2 4 6 and 8, cylinders 1 3 5 and 7 were all sitting at 7+/-. I turned the truck off and restarted it and my balance rates were back to normal between 1-2 +/- on each cylinder and was running beautifully again. The next day I started the truck everything ran smooth, idles beautifully But as soon as I hit the accelerator it bogs down and starts acting like there is a miss but as soon as I turned the truck off and restart it everything goes back to normal.. Does anybody have any idea what might be going on here.. Also The truck has 200000 miles on it Lois told the injectors were replaced at a 175000 with boch remans


if half the block was effected, i would second looking over the wiring harness, maybe something got run too close to a moving part or a hot part and it took a couple days to wear / melt through. As something else easy and free to check, assuming the 5MPH was an exaggeration, make sure you dont have any boost leaks in the intercooler piping. A boost leak will kill your power, make it really hard to accelerate and it will usually blow a bunch of black smoke since it cant burn all the fuel without forced induction.
 

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Discussion Starter · #4 ·
I've been checking harness and everything looks good and I haven't found a break in any wires or anything like that. the codes that I'm getting are P2146 and P2149 along with p0302,04,06 and 08. Those are the ones I can remember right now
 
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