OXYGEN SENSOR ESTIMATE

I Own A 2000 Ford Ranger With A 3.0l V6 Engine 67000 Miles. I Know My Oxygen Sensor Has Gone Out, I Just Do Not Know Which One. I Have...

I Brought My Car To A Mechanic And Shared That I Did My Research And Believe I Need O2 Sensor Put In. I Also Told Him To Put In New Spark...

Is It Worth Buying A Car With All Four Oxygen Sensors Needed Replacing? If So, How Much Would It Cost?

I'm Replacing The Oxygen Sensors In My Intrepid, I Needed To Know How I Would Do That, I Already Priced The Parts, I Was Wondering What...