Ok I have a 94 4runner v6. I am going to replace the o2 sensor, I got the Denso universal sensor from sparkplugs.com (great price too I might add). Now the instructions come with a lot of different wiring diagrams for different cars, but Toyota is not on them :pat: . The plug has 2 black(heat) one blue(+) one white(ground) wire. Now I might be premature in this as I have not climbed under the truck to check the wiring to see if they are labled, but Does anyone know what color wire goes to what color on the new sensor?

 

Try this, it's for Bosch sensors but when I did mine the wiring colours for the Toyota sensor were on the list. Then just swap your colours for the Bosch ones.

http://www.boschusa.com/images/OxygenSensorInstall.pdf

 

Thats a good little chart at the bottom, but I do not see Toyota on it

 

No it doesn't have any makes on there, I just checked the wires on my old sensor and matched the colours with one of the rows. Can't rememder now which one, but it was definitely on the list. Mines a '93 V6 so your's should probably be the same.