BMW have replaced multiple coils for me over the last few years, so that I only have 3 of the originals now in the car.

When they suspected the coil was at fault a few weeks ago, they showed me the data on the computer, and they proved it was the coil by switching a good cylinder with the misfiring cylinder, and the misfire now started on the other cylinder.

As for replacing the coil myself, yes I could, but I have no way of diagnosing that the coil is faulty. What software etc can I use to check these error codes myself?

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