[DLucian]

Greetings everyone,

I have a question regarding the live mysfire counter parameter from the DME (that you can acces with bimmerlink or any other diagnostic tool).

I own B48B30B - 125i with a low stage 1 (around 268 HP, just slightly over the stock power the B48B30B makes on the 3 series). It's a custom map made by a garage with very good reputation and expertise. I had this map for the past 20k km and it's been fine. Car has around 190.000 km currently and was always run on 100 octane fuel permanently.

When scrolling around some parameters, I noticed that the live mysfire counter would often go to 1 and back to 0. This would happen quite frequently. It almost never happens under WOT but rather when lifting off the gas.

Initially it was only detected on cylinder 2. I went ahead and changed all the spark plugs (coils are relatively new as well and spark plugs were around 30k km old) and now, this happens on all the cylinders (used OE NGK plugs).

How can this information be interpreted? Is it normal for it to change from 1 to zero permanently? It never remained at 1, always came back to zero.

Car also has no fault codes and no actual running issues. In few cases the idle is not perfectly smooth but it's pretty rare and mostly on cold starts.

Thanks for your inputs.

[IJO]

It's not worth worrying about.
If you had not looked for it, you wouldn't be aware of it.
As we say in the UK "ignorance is bliss".

[DLucian]

Small updates, if anyone else would ever end up in my situation, I checked 3 other B48s and all of them had the exact same manifestation. 2 of them were the B48B20A versions (on Europe spec 20i) and one was the B48B20B (also Europe spec, 30i).

One of them had around 40k km and is 4 years old.

So, similar to what IJO was saying, I am not sure what that parameter is intended for but I am 99% sure that it's nothing to worry about and it should be ignored as long as there is no actual misfire error stored within the fault codes.