Land Rover Repair: 97 discovery oxygen sensor, wire sensor, oxygen sensor

Question
My wife drives a 97 Discovery with a P0150 error code which I am told means that the oxygen sensor between the exhaust manifold and the cat. convertor is bad.  I purchased a universal O2 sensor for the replacement.  I was given a three wire sensor.  The Discovery has a four wire sensor.  Can a three wire sensor replace a four wire?  I was told that the three wire uses the sensor case as ground therefore the fourth wire is not needed.  If the three wire can replace the four wire, how do I connect the wires?  I only know which wire is the signal wire and which wires are the heater wires on the new sensor.  I do not yet know which wires do what on the old sensor.

Thank you for your time,

Wrick

Answer
Hi Wrick,

Is it not too late to return the sensor and find the correct one?  I'm doubtful that you could adapt this 3 wire sensor to your 4 wire Disco.  I would not take the chance.  

I'm sure you can find the correct o2 sensor on the internet: www.oxygensensors.com

Best of luck,

JohnMc