I'm replacing the steering rack and had to disconnect both downstream O2 sensors beforehand. Now I can't tell which sensor goes to which connector. They are both the same. Yea I got a 50 50 chance, but I'd like to get it right while they are more accessible with the subframe lowered. Can I leave one disconnected and use a scan tool to show which bank is disconnected and go from there? And if so, what is bank 1 and bank 2? Radiator or firewall side?
Connecting downstream O2 sensors, 1999 Taurus.
- Thread starter atikovi
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IIRC, bank 1 is radiator side. Had a '98 Taurus wagon years ago.
And scan tool was no help. In live data, showed all O2 sensor heater circuits good even when the one O2 sensor was disconnected.
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- Jun 25, 2021
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Have you tried looking on the internet to see if you can find the diagram for the vehicle?
Ground the signal input on one of the sensor connectors. That WILL set a code. Then you can use the code to figure out what sensor it is.
EDIT: If doesn't set a code (fast enough or it requires the engine to be running), then look at the O2 sensor live data as you ground it, it should cause the voltage reading to drop, since as I recall there's a bias voltage on the O2 sensor wire that holds it above ground when not connected.
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Thanks for the correction. My memory ain't what it used to be.
Are the wiring colors going to both sensors the same?
Couldn't really tell as they were covered. Put them back now and will see if I get any codes.
Bank 1 is firewall on Fords. That FixYa link is complely wrong.
