Bosch O2 sensor Q's

[David Piper]

Jason wrote:

At 03:32 PM 10/6/98 -0400, you wrote:
>I just bought a Bosch p/n 13190 3 wire O2 sensor to replace the 1 wire
>that I currently am running.. How do I wire the thing, it has 3 wires,
>WHITE, WHITE, BLACK and labeled  A,  B,  C  respectively, is there any
>test I can do with a DVM to assure I don't hook it up wrong.. Secondly I
>am thinking of running it off a relay triggered by the fuel pump relay,
>is this a good idea?  Thanks. Jason

The two white wires are probably the heater and the black wire and shell is
the O2.  You can verify this by testing for continuitybetween the two heater
wires...about 5 ohms.  The one that has infinite resistance to all other
wires or the shell is the O2 signal wire.  This wire must be insulated well
and all terminations sealed from any moisture, since it is high impedance.
Your DVM must have over 1 meg internal resistance to read accurately.  My O2
was reading over 2 volts the other day when I discovered moisture on the
terminations in the plug from the previous days car wash.

The O2 sensor can not measure A/F, only if mix is rich or lean.  Part load
cruise on my custom turbo runs 0.80v and full load WOT runs 0.90v.  Anything
less than 0.70v is probably too lean. 

TurboDave