Misfire Cylinder 1

[jamiec32]

I keep getting a CEL for misfire cylinder 1. I have changed the coil pack and still comes back,even swapped with another coil to see if it was defective...Could a bad 02 sensor cause this? Usually does it when you first start the car when its cold.

[MIKYZZ4]

First, what is the actual code, and from what type of scantool?
I would inspect sparkplugs and replace if worn or fouled.
If nothing changes, try swapping injectors.

[EdwardStewart]

I keep getting a CEL for misfire cylinder 1. I have changed the coil pack and still comes back,even swapped with another coil to see if it was defective...Could a bad 02 sensor cause this? Usually does it when you first start the car when its cold.

Are you getting other codes? The 2005 330ci we have had similar issues, but was throwing some O2 sensor codes as well. O2 was not the issue and thus let us know if you had other codes.


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[feels1]

Since you only swap coil pack, then I will suggest to swap spark plug as well

[Jackson42]

Much as I hate to say it, do a compression check. On both our E46s, intermittent misfires led me to run compression checks and I found that both of them had low compression in several cylinders. Both had badly pitted exhaust valves and worn exhaust valve guides.

[jclausen]

Swap spark plug