2005 Nissan Xterra This Truck Codes Bank 1 2

There's about 50 codes related to oxygen sensors and over 50 pages in the diagnostic manual related to determining the cause. When you get the same codes for both sides of the engine at the same time, unless it is related to some wiring the sensors have in common, the problem is going to be with the way the engine is running, not the sensors. The sensors are only reporting the condition and the computer is setting the codes because it is not happy with the condition. Replacing the sensors won't solve the cause of the problem.

When you know the exact code numbers and want to pursue it further, please list the engine size.