Haha good guess, It is a us spec 94. Sorry about that, end of the day oversight.
So yes, the FSMs and EWD you and others have provided on here are a great resource. Im probably overlooking something but, even with that the wiring diagrams im still not certain which wires to use for the signal, and the ground. Toyota never intended for these O2 sensors to be used on this truck, but the original NTK are NLA. Other forum members have reported success with these bosch 15728 sensors.
Toyota does not specify which is the signal and which is the ground for the o2 on the diagram, both wires go to the ecm, but it has to either be ox1 or ox1+ (and ox2 and ox2+).
Im not sure if that + is for polarity, or for auxiliary, or what, however when i put the key on i get 12 volts from b+ (to ground), 1.02 volt from ox1+, and .79v from ht1, and 17.8mV from ox1.
That leads me to think they are referring to polarity, but im not sure, especially since ox1 is shielded and ox1+ is not.
Like i said before other members have posted conflicting results in regards to wiring the bosch univeral.
Here OX1+ is used for signal, and OX1 for ground and success is reported. post #11 and 12
guys, need help i found that my outside cat o2 sensor is not hooked up anymore and that is why i'm getting a code 21 wheni read the codes, but the PO must have replaced broke off the plugs but neither the harness or the o2 sensor have plugs, and there was a weird connector device, the problem is...
forum.ih8mud.com
Here (and in the video i linked) OX1+ is used for ground and OX1 for signal and success is reported. with multiple follow ups for success, im assuming they wired it as he clearly states. post #1
Figured I'd share my research ansd R&R into 02 sensor replacement for the 93-95 (pre OBD II) trucks. After my bonzai trip out east with my tandem axle trailer to pick up the back half of a Honda CRV in MD, my SC toasted the original 02 sensors climbing the hills of WV. Bad idle, total crap...
forum.ih8mud.com
I don't know maybe it will work either way, but while its not the best reference because its an old sensor that was throwing codes with a heater that tested dead, non of the wire on my NGK NTK sensors had much continuity with ground at all, whereas the bosch ground wire has full continuity with the body of it.
the bosch sensors ground wire has full continuity (around one ohm) with its case, that would consequently be grounded to the engine when installed, It seems illogical for the OX1+ which was sending one 1.0 volts (with the ignition on) would be connected to it, when the OX1 was sending 17.8mv with the ignition on.
To further muddy this the 60 series has nearly the same layout as the 80 series for its o2s, ( refer to the pics in my first post) the schematic is near the same. But they wire what would be OX+ direct to ground.
Then again, OX1 and OX2 go up to the test connector, and not OX1+ or OX2+
I checked the number on the sensor, and they are the bosch 15728
So, is OX1 or OX1+ the wire that should be wired to the bosch's ground wire?
What do yall think?
Help would be greatly appreciated!