Can anyone tell me how the OS2 cable in a 2000 4Runner is routed from the sensor to the "brains"?

 

I am guessing you mean the Oxygen Sensor.

They are both part of the Engine Harness.

both unplug from the harness.

most often attached to the right side of the transmission or in that area.

It is all bundled together and goes through the firewall on the right side to the ECM

Behind and below the glove box

 

Thanks.. Sound like thats a pretty tight spot to find the signal (blue), ground (white), and black (+12) running from the rear sensor. Any advice on a better way to pick those three up?

 

You can check those wires where the sensor pigtail plugs into the harness

The very best way is to make some jumper leads with male and female pins.

You really don`t want to go poking holes into the insulation or at the plugs to let all the weather in

The other option is at the ECM Sometimes things need toi be unbolted to gain access.

 

Many Thanks.... Looks like there is no easy way to get there. The ECM is located under the center panel? Somebody is going to have to post a UTUBE on this to make it simple. Did one of these on a 95 Camry. Was a piece of cake. Thanks again for your input

 

Behind and a little lower then the glove box