View Full Version : o2 sensor

12-05-2005, 09:42 PM
hi. i have a thread going on another forum thats not getting very many replys. I have my car just sitting there and i need to get it running soon. I cant figure out where the O2 sensor should hook up in my 88 celica gts. Someone told me to look to the right of the exhaust manifold and i couldnt find anything. Can someone send me a picture of where to look or where the wire is coming from? The wire coming out of my o2 sensor is a 2 wire black and grey (or white?) wire and is about 1.5-2 feet (though if its just to the right of the exhaust manifold i couldnt see why you would need that much wire). Also would not having the o2 sensor plugged in make it double the maximum allowables for the emissions test? Anyway thanks for your help.

12-05-2005, 09:48 PM
Don't think this belongs here....but.

On the 89GT(mine) it's right in the middle of the exhaust manifold, drivers side,(right side when looking at engine). Yes, it needs that much wire because on mine(the GT, 3sfe motor) the wire runs up to near the MAF.



12-06-2005, 12:04 AM
thank you very much for the fast reply.

I went outside to look at my car and coulnt really find anything. I have no plug on the end of my o2 sensor wire, its just two wires(black and white). I followed the wire that yours is plugged into and it just goes into one big fat wire. i was looking for a plug on the entry of the small wire to the fat wire and found nothing. Maybe the plug has been pulled out of the entry area where the o2 sensor plug should plug into. The only thing i found was a skinny yellow wire with a small black stripe on it coming out of the entry. maybe thats something? also i have a 3sge so it might not be exactly the same. thx for your help on this situation. anymore help would be appreshated.


12-06-2005, 12:15 AM
take some pics and post them up

12-06-2005, 12:28 AM
That pic above is for the 3SFE, so it'll work only for the 86-87 3SGE.
The 88-89 3SGE motor has the O2 sensor mounted underneath, on top of the front exhaust pipe in the engine bay. It's mounted on the top surface, so it's a real bitch to reach. Get underneath to see it.


12-06-2005, 12:58 AM
Thanks Rick. :)

I wasn't sure..

12-06-2005, 03:09 AM
k so heres the picture. the red circles are the wires coming from the o2 sensor from the center of the manifold. the blue circle is that yellow wire coming from one of those wires in that area. that white circle is that slot thing that looks like something might fit inside it? anyway maybe someone can tell me where it goes around that area. thanks


12-06-2005, 04:37 AM
[QUOTE=Turbo515]...that white circle is that slot thing that looks like something might fit inside it? anyway maybe someone can tell me where it goes around that area. thanks

Don't worry. Here's a pic. That slot just fits onto the metal tab on the tranny to hold the harness in place! It's nothing serious :hehe: .

12-10-2005, 08:55 AM
hmm, still cant figure this out.

anyone help please?

Dr Tweak
12-10-2005, 09:16 AM
So, just so I understand, your 02 sensor is in place, but the two wires that come from it aren't hooked up anymore?

Also that yellow wire may be your oil pressure warning light or guage.

What is the history of the car? Is this an engine swap? Does the engine run?


12-10-2005, 08:06 PM
The engine runs fine after its warm. I guess that would be why my oil pressure gauge has been reading nothing for the last 6 months. There has been no swaps in this car, however im thinking about doing one to the stock engine with low miles. Yes my o2 sensor is connected into the exhaust manifold. Im not sure how these all got unplugged but now i guess i have to figure out where everything goes. The knock sensor is also unplugged however im not going to worry about that right now. I just need the o2 sensor working so i can take it through the aircare emissions test. thanks for your help.

12-14-2005, 02:34 AM

12-14-2005, 09:49 AM
Aircare? You in the GVRD?

12-15-2005, 12:28 AM
i live in guilford(surrey)

12-15-2005, 06:25 AM
This is from the factory '88 Celica wiring manual. It shows a 4-wire O2 sensor. If yours only has 2 wires, white and black, perhaps someone has butchered the wires and installed an aftermarket O2 sensor (?).

In any event, you can probably hook up your white wire to the white lead (#3) to get it working. The ECU should be able to read it. The other wires are for time and heating elements, which probably explains why your car runs better after it's warmed up.

PS. To clarify your pic above, the white circled thing is just a clip to hold the wire harness in position. There's no live wiring in there at all. Take another look at my pic with it red circled, you should be able to figure it out :)


12-16-2005, 03:57 AM
okay thats great, thanks. I had someone put a new O2 sensor in about a year and a half ago and i guess they put in the wrong one :( anyway im not very good at wiring diagrams but ill look around the right side of the exhaust manifold tomorrow for a white wire. Also someone told me that the black one should be the ground. would it hurt to ground it to something or should i just do it? Thanks very much for your help, looks like im on to something.

-also is there anyway to know if its hooked up or not? or just take it to aircare and see if its better? thanks

12-16-2005, 05:46 AM
Here's the test:
(Doesn't look easy though.. :ugh: )