what does this mean is it an o2 sensor or means oil change ?????? just started a week ago

 

It usually means a routine maintenance interval. It could be an oil change or it could be oil change/tire rotation/air filter/ cabin filter change. It should give you a code such as A or B followed by a number or numbers. For example an A1 service is a oil and oil filter change. A A2 code usually means a Lube, Oil, Filter+tire rotation. In contrast a B1 service is usually a Lube, Oil, Filter+tire rotation and balance+wiper blade inserts+inspect a bunch of things. A B2 service is usually all of B1 service+ Engine Air filter and Cabin Air filter change. Hope this helps and not confuses you.

Edit: Do you have a 2009 TL? From your screen name, seems like you have a 1998 RL? If it indeed is a 1998 RL then the above codes may be the same but the work performed might be different since its 11 years old.