Hello all. I have a 2018 Silverado LT Z71 with a 5.3L that is throwing a P0301 code. Misfire cylinder 1. Usually, it starts up and runs fine but after a quick test drive it always drops a cylinder and throws the code. Then it will go back to running fine. It’s very intermittent. There is no ticking or knocking that I can hear.
So far this is what I have done

8 New plugs
8 New wires
8 New injectors
Moved coil from cylinder 1 to 3, no change.
Checked compression (around 210 psi in all)
Pulled valve cover and checked that rockers were operating properly.
Checked vacuum lines
Tester MAF sensor
Tested O2 sensors

None of this has helped at all. I’m kind of at a loss here and hoping somebody came across this with their Silverado and has the magic cure! Thanks so much in advance

 

did you visually verify the cylinder has good spark?
You may want to inspect the lifters.

 

I did check spark, seems to be fine.
as for lifters, I pulled the valve cover and fired it up. The rockers are operating properly and arent making any noise. I tried to upload the video but it’s too large to attach.

 

you can upload videos to you Youtube and post the link here.

 

this may work as well. Unfortunately the camera shutter speed makes it look like the rockers are pausing. But they are not

https://share.icloud.com/photos/0250...nGBkB2hK3fzXJg

 

Did you check the harness and connector to the coil on the misfiring cylinder to make sure that are no intermittent connections there? Check all connectors in the harness, all the way back to the ECM.