Cause
Cracked coil body tracking to earth
A crack in an ignition coil's insulator letting the spark track to earth instead of jumping the plug gap. The spark takes the easiest path, and a carbonised track across a cracked body is easier than a plug gap under compression.
So the misfire appears under load and not at idle, because cylinder pressure raises the voltage needed at the plug while the track's demand stays constant. A thin dark line down the insulator is the visible evidence, and tracking is often audible or visible as a blue flicker in the dark with the engine running. Oil in the plug well accelerates it by attacking the boot, so check the well before fitting a replacement — a new coil into an oily well fails the same way.
Typically an easy fix. Often worth checking before paying anyone to look.
Some of these codes mean you should stop driving
1 of the 1 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (1)
Codes where this is a likely explanation first, rather than merely a possible one.
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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