View Full Version : wire diagram o2 sensor
07-16-2004, 08:55 AM
was tryin to find a wire diagram for the o2 sensor for my 99 grand am gt... i am installing a a/f guage an was wondering wich wire it is i hook it up to
07-16-2004, 09:20 AM
Cavity A= Oxygen sensor Low (usually TAN wire)
Cavity B= Oxygen sensor High (usually Purple wire)
Cavity C= Ground for heater element
Cavity D= Ignition power for heater
In newer vehicles the ground wire gets replaced by a control signal from Powertrain Control Module so the heater can be controllered instead of just turned on with ignition.
07-16-2004, 09:55 AM
Purple wire is the signal wire.
07-16-2004, 10:43 AM
07-17-2004, 11:36 AM
ok i attached it to that... an my a/f guage is bouncin all over the place... only stays steady when i have the pedal floored... bad a/f guage?
07-17-2004, 07:52 PM
anyone have any idea why its doin that?
07-17-2004, 08:43 PM
That is completely normal. It's more of a multi-colored LED light show than anything else.
07-18-2004, 07:16 AM
how is that normal when its bouncin all over the place?
07-18-2004, 11:59 AM
Because the O2 sensor readings are all over the place. The gauge is just relaying that mess of data.
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