For a car with less than 140,000 miles, that is also less than 8 years old...having the sheathing around the fuel injector wires completely fail is a gigantic red flag for the state of GM. Failing harness was caught early in my case, causing only random misfires, and did not cause major drivability issues or safety concerns, but I can imagine what others have or will go through because of terrible design quality at GM. Only fix is to replace it with another GM harness that will need to be replaced in another 5-7 years because of the same failed sheathing. In theory, EVERY SINGLE LS/LT engine manufactured from 2015-now, which has dual injection (MPFI & GDI with two fuel pumps), has a similar fuel injector wiring harness design.
If you add this issue to failing in-tank and GDI fuel pumps, failing lifters, failing 6L80 transmissions, failing AC systems in the previous generation, as well as the massive recall on the 6.2L engines, and you've got two entire generations of GM trucks/SUVs that are absolute trash. All cars have their own fixes, they're just machines, but GM looks to be far past its golden era of giving a damn about its customers and long-term reliability. If you've got the P0300 random misfire code and your mechanic is trying to sell you a top-end lifter and cam job, ask him to run the shutoff checks and confirm the fuel injector harness before yanking the heads. (The intake has to come off to check the harness, so if it's not the harness, they're already into the removal steps for the lifters.) Might save you thousands.
For a car with less than 140,000 miles, that is also less than 8 years old...having the sheathing around the fuel injector wires completely fail is a gigantic red flag for the state of GM. Failing harness was caught early in my case, causing only random misfires, and did not cause major drivability issues or safety concerns, but I can imagine what others have or will go through because of terrible design quality at GM. Only fix is to replace it with another GM harness that will need to be replaced in another 5-7 years because of the same failed sheathing. In theory, EVERY SINGLE LS/LT engine manufactured from 2015-now, which has dual injection (MPFI & GDI with two fuel pumps), has a similar fuel injector wiring harness design.
If you add this issue to failing in-tank and GDI fuel pumps, failing lifters, failing 6L80 transmissions, failing AC systems in the previous generation, as well as the massive recall on the 6.2L engines, and you've got two entire generations of GM trucks/SUVs that are absolute trash. All cars have their own fixes, they're just machines, but GM looks to be far past its golden era of giving a damn about its customers and long-term reliability. If you've got the P0300 random misfire code and your mechanic is trying to sell you a top-end lifter and cam job, ask him to run the shutoff checks and confirm the fuel injector harness before yanking the heads. (The intake has to come off to check the harness, so if it's not the harness, they're already into the removal steps for the lifters.) Might save you thousands.
- Charles B., Burlington, NC, US