[modthispny]

If you search my post history you'll see that I removed the resonators off my 2019 M550i to the enjoyment of very nice burbling/back-firing on upshifts and downshifts.

Last week I noticed the car was a bit quieter on some sport plus pulls, and didn't really hear the burbling/back-firing that I'm accustomed too. I thought maybe one of the baffles was stuck but it was not. I could still get it to burble/back-fire but not as consistently as I used to be able to.

Gas has been the same (filling up at same station), driving habits have been the same as well (given ample time to warm up, etc) and always in sport plus.

I know the burble/back-fire is done in sport plus by messing with the fuel tune, but curious as to why the frequency has gone down so much the past week.

Could it be that the gas stations 91 gas is a bad batch? I just filled up today so will take about a week to go to empty, but any other ideas as to why?