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Q: Engine misfire, P0300 code

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Engine ran fine yesterday, today it has a misfire & flashing CEL. Had the code checked shows p0300. removed spark plugs & they are all clean, light brown. Wouldn't a misfire cause the plugs to be black?The misfire & flashing CEL occurs on acceleration, when coasting the CEL goes out. Had the same problem before & it was the #2 coil, but it had a fouled plug also.

My car has 170000 miles.
My car has an automatic transmission.

A: It is not the color of the spark plug that ...

It is not the color of the spark plug that determines its condition - it is the appearance of the electrode on the spark plug. If one of your ignition coils has gone bad before and it was the only one that was replaced, it is possible that another one of the ignition coils has gone bad as well. When each cylinder has its own ignition coil, it can sometimes be very costly to replace all of them at the same time but in a perfect world all of the ignition coils should be replaced when the spark plugs are replaced.

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