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