I am wiring in 4 wire universal o2 sensors on the 850. The original ones have 2 white and 1 grey 1 black. I need to know which ones are the heater wires, computer signal, and ground wires?????

Thank you very much, I dont want to damage any thing....

From my experience for engine 5252S (10 valves) works only original NTK
from dealer. Spent a lot time and money for Bosch universal but in vain.

To answer your question, the signal wire is black, the ground is gray and the two whites are heater wires

bl

Is your universal a Bosch sensor? if so, then the color of the wires shoud be the same as your original, just splice and connect and use heat shrinking tube,

The bosch universal is PN# 15717
--
'88 240, '92 745, '98 v70 John, Tampa Bay

where did you bought your universal O2 sensors?
--
Ken

www.swedishparts.net

$47 for the universal sensors

$47 is a very good price but I've heard a lot of problems with people using the universal O2 sensors

You car a turbo or N/A ?
--
Ken

What kind of problems have you had? Where can I find out more? I started the engine after the new sensors were installed but now I can not get the engine to start???

My original sensor was NTK (Titania, red, yellow,black and white wire) I thought
it is regular most common zirconia oxygen sensor and tried to use Bosch universal
sensor. If you installed appropriate sensor only what you have to do is to reset
computer and must be O.K. If there is some problem with sensor computer continue
to work taking information from stored memory. I drived car two weeks without
oxygen sensor, mixture was very rich (no feedback).

I think there is a thread over on bay13.

What is Bay13? I must have missed a step.

Bay 13 is a repair/maintenance link over at www.volvospeed.com Very, very useful!