1. two bars is about 400 ml, or less than 1/2 qt down. So, in reacting to that, you should have added < 1/2 qt
2. Oil lights come on fir various reasons - pressure, level primarily. Was it oil LEVEL nto pressure?
3. If so, it certainly sounds like a sender. But step #1 is to verify it. Let oil find its level (car on a truly level surface) and check the dipstick.
Marc has written a detailed note on the location and operation of the sender. I cant recall if its easy to access or not, i suspect not.
Good luck.
Grant
Grant
gee-lenahan-at-gee-mail-dot-com