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Discussion Starter · #1 ·
I have a 2003 s10 4wd with a 4.3! I’m getting a p0305 code which is cylinder 5 misfire! I’ve changed all plugs, wires, distributor, cap, rotor and new fuel filter! Still getting same code very rough idle and really bad fuel mileage! I am now lost at what else it could be and I don’t want to keep spending money and throwing parts at it that doesn’t fix the problem! Someone please help!!!!
 

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B4U Task Force Admin
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Could be a bad FPR or leaky FI lines to the injector.


B TW...check the section you're posting in. The correct section will get you better results.
 
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Engineer
2003 S10 4.3L 4wd Crew Cab
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Just a suggestion because I was in the same boat ready to change out the spiders for a misfire on #5. I changed the wires and all that when it started happening. I was working late in the dark with the truck running when I could see light coming from my wheel well. There ended up being a small cut in the plug wire and it was arcing to the heat shield. I taped it up with heat shrink and it fixed my problem. Worth a look before pulling everything apart.
 

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Discussion Starter · #6 ·
Just a suggestion because I was in the same boat ready to change out the spiders for a misfire on #5. I changed the wires and all that when it started happening. I was working late in the dark with the truck running when I could see light coming from my wheel well. There ended up being a small cut in the plug wire and it was arcing to the heat shield. I taped it up with heat shrink and it fixed my problem. Worth a look before pulling everything apart.
Thanks I will look into it! I can only hope it would be something that simple lol
 

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B4U Task Force Admin
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Thanks I will check those! I’ve seen a lot of people saying the spider injectors going bad is a common problem?
With a 2003, you should have the upgraded injectors...doesn't mean that can't have bad injectors, or the lines leak.
 
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1997 Sonoma 4.3 4x4 Flatbed Auto 9,000 miles
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I’m not exactly sure how an 03’ is but I also did have a #5 cylinder misfire and it ended up being broken inside the spark plug boot. But I also did fire the truck up at night and popped the hood and noticed the coil was arching off of the little mount that mount the coil to the valve cover. I bought a new coil too just because I knew it would eventually cause a random misfire as well. But you should definitely fire the truck up in the dark at night and see if one of your wire or coil is arching off of something. Might not be the solution but its worth checking. Good luck!
 
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