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Cylinder misfire after replacing coil

Yesterday my car began shaking and my check engine light came in. I had it read at autozone and it said cylinder 4 misfire. I checked the plugs and they looked good. I figured it was the ignition coil, so I switched the number 4 coil over to cylinder six and had the code read agin. This time it said cylinder 6 misfire, I figured I had found the problem and bought a new coil, installed it and the shaking is still there. I haven’t had a chance to take it back to get the code read. It just seems odd the the problem changed cylinders when I moved the coil over, but replacing the foil didn’t fix it. Any suggestions?

A bad new coil would explain it.


Good detective work there OP. Change that coil over to a different cylinder, see if the problem follows along w/ the coil again. If so, I think @insightful has it, you just got unlucky on the coil purchase. While you have the coils removed you could test the resistances I suppose. Usually the secondary measures around 10k ohm. There’s often a test for the power transistor too, you’d have to look it up how to do it in the service manual.

Edit: There may be some anti-static procedure you should follow when replacing coils. Maybe somebody here knows. If the power transistor got a static shock in the process you could turn a good replacement coil to a bad coil rather quickly.

you switched coil 4 to 6 and the problem moved to 6. I hope you installed the new coil on 6, not on 4, unless you moved them back again :slight_smile:

Seems like a lot of driving with misfire. Is that bad?