WHAT TO DO WITH THE WIRES TO MAKE THIS WORK:
Your original O2 sensor has two wires of one colour (white). These wires are for the heating element. The third wire (black) transmits sensor data back to the computer. Get a UNIVERSAL 3-WIRE O2 SENSOR from your local auto supply store. (Bosch #13077 ??) Follow enclosed directions, cut off the old O2 sensor, and splice/solder/wrap the new unit onto the matching white and black wires.

If your car has a 3-wire sensor, then replace it with a universal 3-wire sensor. The heating element allows the O2 sensor to quickly reach operating temp (600 degrees). After starting the car, the engine computer will test the O2 sensor in 45-60 seconds. If you replace the 3-wire sensor with a 1-wire unit, the sensor will not warm up fast enough. The computer will then set the O2 sensor code and turn the Check Engine light on. If you reset the codes and restart the car, it will keep doing this over and over. (I learned this the hard way!)

COST: 1-wire universal replacement - $18
3-wire universal replacement - $45
3-wire OEM replacement - $120 (?)

The only hard part might be "untwisting" the wires if you try to do everything underneath the car. Simply pull the entire sensor and cable, noting where you unhooked it, splice/solder/wrap as needed, install the new sensor, then run the connector cable back up into the engine compartment. A wire coat hanger may come in handy to pull the wire back up!

[[ southern fried volvo '91 240 126k mi, with new O2 sensor! ]]

Auto Zone sells a universal 3 wire O2 sensor that works perfectly well on my 240 and will work for you too.

Check the archives, and then go to:

http://www.homestead.com/volvo2/O2sensor~ns4.html

everything is explained there.

good luck.

"i remember visiting this site once sometime ago.there was an on going discussion about the pros and cons of hooking up an early,single wire 02-sensor on a 1989 240 B-230 non turbo automatic.i want to do this,(i think?)
what to do with the wires to make this work? "

The wires to make this work. 2 of the wires are for the heater, so you just leave those alone and hook up the single wire to the 02 feed to the computer.

"what problems might i encounter?
climate-(midwest)
reason for wanting to do this -(cost of preheated sensor)
thanks for any and all help "

When is the last time u bought an 02 sensor? how much does the 3 wire one run?
Have you checked all the options? www.alloemvolvoparts.com www.fcpgroton.com

I am thinking of converting to a heat 02 sensor, sure it might be more expensive, but it heats up the sensor much faster, and the computer goes into closed loop mode using the feedback from that, which helps gas mileage and driveability.

Especially where you are, I would use a heated 02 sensor since the winters are much colder, and getting the sensor to operating temperature is best in my opinion.

just some thoughts, hope it helps.

take care

Luke
82 242Ti 169k miles
http://home.ncn.com/~pcguy

it may be cheaper to buy a universal three wire sensor.

Also I remember reading about the mustang bosch sensors being the same kind but much cheaper.