Service kit wont help you here.
You need to read the codes with a diagnotics cable or even bluetooth obd adapter. Then you will know in which cylinder it is misfiring and then you can start your diagnostics from there.
Usually its one of the coils, they known to fail. But it could be something else.
If you really want to skip the code reading, then you can start with pulling the coil out and put it back in 1 by 1, whilst the engine is running. If you pull a coil while running and engine doesn't re-adjust timing, then that is the cylinder it is not firing on. If you pull a coil, and it re-adjusts timing, you will know by seeing the engine look like it will die but then re-adjust and go again. If it does this, that cylinder is working.
Then to see if it is a coil, swap a working with non-working one and watch again if engine re-adjust timing to fire.
So it could be as cheap as a single coil, but if it is not a coil, then the problem can go deeper.
Hopefully either a coil or spark plug and not something worse.
