2003 Passat ABS and ESP Lights

I have a 2003 Passat V6 GLX.

The ABS and ESP lights come on sometimes and I'm not sure why.
I had it diagnosed and was told that it was some moisture on the sensor. The lights came on again recently and it really feels like the car has lost power since then.

The transmission seems slow to change gears and I just can't feel the same power that I'm used to.

Also, last week the alert center told me to "Stop Motor" immediately because oil pressure was low. I was near my destination so I got there and checked the oil. It was low so I put some more oil in and had not had a problem until these lights came on again.

Could these problems be related and what could be causing the loss of power?

Thanks.