I have codes p1167, p1166 and po159 which seem to read Heated oxygen sensor 2 bank 2, heated oxygen sensor (bank 2 sensor 2) lean shift monitoring (bank 2) and 02 sensor circuit slow response (bank 2 sensor 2). Are these something I need to replace right away and will CEL turn on again if they are problematic since I just reset the ecu to clear the codes.

 

I would say you need a new O2 sensor

 

Any time you're throwing an error code you need to fix what ever's causing it!
Gary