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Chevrolet Express
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2010 Express 2500 Randomly Rough/CEL Flash

Old May 20, 2022 | 7:53 AM
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Default 2010 Express 2500 Randomly Rough/CEL Flash


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​​​​​​Replaced Cats front 02 sensors the injectors were supposedly replaced. I'm having very intermittent misfire almost stalling. If I unhook battery let it sit an hour start back up and idle it's fine for over 30 mins no issues as soon as I start driving over bumps/highway speeds it will start acting up. Not sure if wiring issue? PCM?

Last edited by HardlyBoostin; May 20, 2022 at 7:56 AM.
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Old May 20, 2022 | 3:25 PM
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Look at the injector cylinder numbers. Notice anything?

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Old May 20, 2022 | 3:42 PM
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Yes I checked fuse good. I am assuming it's something with fuse box or power wire going to run new wires to each injector and see if helps.
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Old May 20, 2022 | 3:46 PM
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I bet there's a separate wiring harness for each bank of injectors and the bank 1 harness is faulty. I don't think they have separate fuses.
Problem doesn't necessarily have to be in the power circuits. It could be the signals going to the injectors too.
First I would just look for the obvious signs: chafed/nicked wires, corrosion in the connectors, and bad ground points.
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Old May 20, 2022 | 5:50 PM
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Yes each bank has seperate fuses. Could be ground/signal doubtful that all 4 on one side having ground issues. Sounds more like voltage drop/short. No the injectors go to PCM no connector for ground and power goes to fuse box.
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Old May 20, 2022 | 7:30 PM
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Right you are
Fuses 52, 55
Fuel Injection electrical schematics - Chevy & GMC Vans
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