hear a whinning in transmission when giving car gas to excellorate on 1994 BMW 540i

I hear whinning sound in transmittion when excellorating. What could this be? I dont notice any lose of power or slipping. Strong excelloration, shifting good. I also have a check engine light on, it is for o2 sensor in exhaust. would that give me some trouble. Thanks

Asked by for the 1994 BMW 540i
Transmission could be worn, general wear and tear.
Check the trans oil level and condition.
Nothing on these trans can be adjusted and filters are not fitted.
The 02 sensor fault will not be linked to your trans noise.
Have the noise checked by your nearest BMW dealer or mechanic found in the "Find a shop" tab at the top of the screen.
As acceleration noises can be linked to diffs and in some cases misdiagnosis of tyres or bearings.

Good luck