Do I have RMS?

[jlawrence54]

Hello all. I have a 2000 Boxster S 6-speed manual with 121K miles. After an oil change I had a significant cloud of oil at start up but, car drove fine (lots of power, good temp, no noises). I drove 85 freeway miles with no visible smoke, even when I stopped at lights nothing visible with temp and power looking and feeling great. I parked it and came back 2 hours later and the initial smoke again but performed fine. When I returned home I plugged it into the computer and it came back with both O2 sensors being bad. Then I check the oil and it was essentially gone, barley registered on the stick. No visible oil leaks underneath. Did I burn through it all? Do I have an RMS issue? I've parked it since. Thanks for any help you can provide.