What does p015b code mean on the chevy cruze?

Code p015b in a Chevy Cruze means that there is an o2 sensor in the bank one has detected a fault. This means that You are either running rich or lean, the meaning is that the air to fuel mixture is not correct. This can make it so that the car will not have enough power or that it will surge. Running the engine like this long term will eventually lead to damage, as well as consuming a lot of gas. You need to take the car into the shop and have it looked at if You see this. Often it is something simple like needing a new filter, but if left alone it will become something complicated.