Rpm drops, help please

[kvvikdrawmcgraw]

I have rpm drops at around 5500, down to around 4000, then back up to 5500 and continues unless I change gears or lay off the gas. They are pretty violent and lurch the car. Its a 325is with a bavauto chip (i believe), and a 410 lsd (dunno if that makes a difference). Help please thank you!

[Hey_You]

Do you still have your stock chip?

[kvvikdrawmcgraw]

No, that would have been a good way to diagnose it though.