i was rebuilding my manual transmission and i seen that my O2 sensor wire was cut, I cant find the wire the O2 sensor is supposed to connect to. Anyone have a Clue where to start tracing the wire?

 

it might be inside the bellhousing, if you have installed your trans. and, it was between the engine and trans.

 

im not seeing the wire, or a plug even, Theres two wires going to the tranny one for the 4WD and im not sure what the other is for. There is a small 3Plug harness thats right next to the oil pressure sensor

 

On the 4runner, it actually comes out of the floor under the drivers side seat.. dunno if it is the same on the truck.

 

How much of an impact does the o2 sensor have? When I did my headgasket change last winter I did the stupid thing of pulling my wiring harness completely out. I had to cut the wires going to the o2 sensor located about under the driver's seat mounted into the exhaust. Well I don't know if I got them hooked back up right and now when the engine is warm there is a slight miss in the idle and the exhaust smells rich. Could the o2 sensor wires not being hooked up correctly cause this?

Thanks,
Rob

 

Anyone?

Rob

 

On my 94 truck, there is a pigtail from the main wire harness that goes over the top of the manual transmission for the O2 wire. You might look on the top of the trans or the on other side for an unconnected pigtail.

 

Bump for an answer

Rob

 

im tryin to understand what your saying... are u sayin u respliced the wires back in and your worried u might have them backwards??? if you run the car for an extended period of time (not long really) with the wires the wrong way around then you will fry your O2 Sensor...

The 02 sensor is very important it tells your computer what level of oxygen remains in the exhaust gases so that it can compensate accordingly

 

Yeah that is what I am saying. How can I tell if I got it hooked back up correctly? It has a little miss at idle when hot. Is that a symptom?

Rob

 

i have the same problem on my 88 4x4 22re. The o2 wire is cut right at the sensor on the exhaust manifold. Ive been looking for a cut wire or pigtail for weeks...no dice, i was told its suppost to be by the brake master cylinder wiring harness. I havent found anything. Ive also posted a thread on this and had no help. Even the color of the wire from the computer would be helpful on tracking this down...By the way, who cuts off a 02 sensor wire or any sensor wire for that matter!!!WTF!!!

 

I also located the o2 sensor by the catylytic converter, its plugged in...the harness comes from under the drivers seat like the 4runner. If you cut your wires, they should be color coded?? If not i dunno, mine has a sheathing all the way on the wiring from the sensor to up in the cab, i cannot tell if they are color coded or not. Arent these suppost to have two o2 sensors?? One on the manifold, and one before the cat?? My truck seems to run well, and no ck engn light either for only having one out of the two 02sensors hooked up.

 

im having trouble even locating my o2 sensor (not to sound like an idiot) i bought the truck cuz it was clean an had the 22re.....it was missing slightly at idle but it has gotten worse and doesnt want to idle at all. went hunting for the o2 and nothing on the mani and the exhaust is cut off from the driver seat back.....(scratches head) went to toyota they printed out a few diagrams....for my 1988 it should be in plain sight on the manifold....hrmmmmm!!!!

 

dezrik ,if i understand you correctly the 86 i believe has the o2 in the exhaust manifold,the 88 has it in the pipe closer to the converter. if the 86 has one in the pipe it might be there as a plug. the truck might have a 88 or later manifold and pipe. look around the exhaust manifold for a one wire plug. if the wire is at the exhaust manifold you need to drill and tap it .you can use a old o2 sensor as a pattern. don't try to lengthen the wire to use the hole in the pipe it won't work,the 02 sensors are differant.

 

The 86 is in the manifold mine melted off where do you find the single wire that runs to the 02 sensor in the manifold?

 

And is it true with out the o2 senser not connected it will run like crap? like 6 miles to the gallon etc etc?

 

i ended up cutting the O2 section of pipe off a dead junk yard 4runner 3vz and its all fixed welded that pipe up and finsih running the exheust out the back. it idles steady but still misses only some times though...i dont get it...thinkin its fuel system?? TPS???

 

Tore interior out there is no o2 sensor wire in the floor board. does anybody know what color the wire may be or maybe a picture of the ecu and witxh pin i could run a wire right off the box?

 

if you know someone that has a similar truck you could see exactly which wire and how it is run. i have not had a efi truck in a while and don't remember exactly where it is located in the wiring harness.

 

im not 100% but the bit of carpet i took up to get to the wire (dead center under the driver seat) it look like it might run straight to the ECU but im not sure....i kno for sure my o2 was a four wire (two white, on gray, one black) hope that helps