Check engine light code P0300?

Hello, here is a guide to to help with a P0300 code and cylinder misfires. Look through both guides. It can be difficult to determine which cylinder is misfiring, especially on a V8. There is a cylinder drop/balance test that most technicians would probably do if they didnt have tools with them, and this is where you would unplug each coil one at a time and see if it effects the idle or not. If theres no change in the engines rpm when you unplug a certain coil, you know thats the cylinder that is not contributing to the engines power output.
What scan tool are you using? On most OBD2 scan tools you can look at the Mode 6 Data, and if you scroll through it, at first it will look like a lot of random numbers, but you will come across Cylinder Misfire data, and it will list each cylinder's amount of misfires that have been counted by the engine computer. Most should read 0. But you will most likely see cylinder misfires counting up on one or more cylinders.
the unplug it test on the coils may or may not be helpful if the engine is not idling well.

https://2carpros.com/articles/automotive-engine-misfire-code-p0300-causes-and-solutions/

https://2carpros.com/articles/engine-misfires-or-runs-rough/

Here is the service information for the P0300 code. It has you checking for good spark at each cylinder, as well as info on how the engine computer detects misfires. Its possible for there to be a bad intake manifold gasket (for example) that is effecting multiple cylinders, so swapping around coils and spark plugs would not have any effect on an engine fault like that.
You should also have live engine data on the scan tool, it shows the readings of the sensors on the engine and can provide a lot of direction. Another example, if at idle, you have high positive Long and Short Term Fuel Trims (LTFT & STFT) and you raise the idle to 2500rpm and those high positive numbers come down towards zero, which is what you want, then you are most likely looking at a vacuum leak, but you need to know these tests and what the scan tool data means.