2003 Yukon Check Engine Light Oxygen Sensor On 2003 Yukon XL-need Help Please...?

Oxygen sensor on 2003 Yukon XL-need help please...? - 2003 yukon check engine light

I have a Yukon XL 2003 and recently had my engine light control to live in some of the things he done to my fuel system and position a new filter, the light always comes from the engine, I was told I diagnoses of 4 oxygen sensors , 2 front, 2 rear, which means but my 2 strikers need to be replaced, this is something that should probably be changed both together? I have 105.000 miles on, and I've never had a problem before, so it was changed within a certain mileage? Am I anything I can do? or you need to connect to a machine to correct it later, thanks for any help.