1997 Lincoln Continental o2 Sensors

There are four o2 Sensors, 2 on the exhaust manifold bank1 sensor1 and bank 2 sensor 2. Then on the front of the catalytic converter bank 1 sensor 2 and on the end of the catalytic converter Bank 1 Sensor 3. Sorry but there is also the Master Air Flow Sensor under the hood that may just need cleaning.
You dont have replace them all Have the computer codes lead you to the bad one(s). Clean the Master first.