Volvo Repair: oxygen sensor, hood latch, oxygen sensor

Question
what is the normal voltage reading in the front and back oxygen
sensor?  what is the best manuel for 95 850 GLT.  Where is the
plug for scanner to read and clear codes.  thanks

Answer
The code ports are by the passenger hood latch area in the engine bay.  2 little black squares.  #2 is for Fuel, #6 is for Ignition side.  The best manual is the factory manuals.  Use chiltons and haynes for toilet paper.  I never had to check voltage on those.  Computer says its bad and you replace them.  Volvo Text book procedure.  Roger