Oxygen Sensors need replaced on my 1998 Buick Lesabre. How many?

[kingthelema]

I have asked NAPA and Autozone about it, NAPA says I have 2 to replace, then Autozone says I have 3. Which one is it?

 

[bobweb]

So just because you've gotten an O2 sensor error code, that's why you need new O2 sensors?? The error codes DO NOT tell you the O2 sensors are bad unless the "heater elements" are burned out. There is no automatic replacement interval for oxygen sensors.