I am trying to smog my '94 4Runner ASAP and I am using two Bosch Universal O2 sensors for before and after the cat. Problem is that I have to splice the harnesses together and I need to know which wires go together. There is a blue, white, and (2) blacks coming from the truck and my new universal sensor has a gray, black, and (2) whites. What goes to what? I need to get this thing smogged by tomorrow afternoon, please give any input you can.

Thanx in advance.

 

is it to late to take them back ?

 

Bosch don't usually work well with Toyotas. Denso or NGK is the preferred; many ppl have issues with the Bosch. If it's not too late, take them back.

 

I'd go with a denso O2 sensor if you can get one. That is what they use for OEM. The wires will be the exact same color and your computer will route the fuel better because you are using the same brand.