Re: exhaust sensor
well you will trigger the warning light on the dash if you turn the ignition on. the engine should run but the fuel/air mixture will not be 100% correct, i would not want to run the car like that for any length of time.
best to buy a new lamba probe anyway considering the age of the car, you will then have great fun trying to run the cable down through the engine bay. if you could have left the old one in place you could have tied the new wire to it and pulled it through, that's how i did mine.