I have a 2015 825i. It seems to be running ok and then it just completely loses power and seems to bog down. We had an issue similar to this before where it ran poorly a few months ago. We checked all the normal things. Compression, new plugs, new fuel filter, etc. After changing the oxygen sensor (didn’t help) changed fuel injectors (didn’t help) we found a spark plug wire with a cut in it. Changed that and it seemed to run well for a few weeks. Now it’s got a huge random loss of power. The exhaust does smell odd and it is a white smoke. I can push the gas and it just doesn’t want to go. I can turn it off for a minute and it will run fine for a little while then lose power again. Any help would be nice.