Lexozz

I bought 2 Bosch O2 sensors from AutoZone, $69.99 each plus tax. The LS requires 4. They didn't have any more in stock. It's pretty time consuming if you don't have the right tools. Here's the part# for those of you interested:

Lexozz

I changed the two O2 sensors after the cat simply because it was an easier reach for now. Here's a view of what it looks like underneath. This is with the old one already taken out on the psngr side. If you notice the harness goes up inside the car.

Lexozz

The tool required for this is a 22mm O2 sensor socket specially made to fit the wire that attaches to it.

Lexozz

I basically had to tear the floor apart to disconnect the on both driver and psngr sides. Why? because Lexus wanted to make the job seem so complicated you'd take it to them.....WRONG Right in between there is the connection.

Lexozz

As you can see in the previous pic the blue and white wires and also two black which you cannot see in the pic are the O2 sensor. The after market sensor comes with the same color coded wires, so all I had to do is cut and splice. Very easy part.

Lexozz

Now when I finally got the old sensor out I had to cut and splice the new one together just about the same length as the old O2, just so I wouldn' t have any excess wire hanging underneath.

Lexozz

Now here's a pic with the O2 detached on the psngr side:

Lexozz

Here's another one, you can see the hole on the floor that the O2 passes through to reach outside/underneath.

Lexozz

Job done $$$$$labor-free. Out with the old in with the new...

Overclocker

Great write up and pics! How often should you change your O2 sensors?

additude

Thanks for posting this info Lexozz, it really helped me out with finding the plug for where the rear sensors plugged into.

I just wanted to add that I use a 7/8" box end wrench to change the sensors out. 7/8" is real close to 22mm and the closed end of the 7/8 slides over the sensor plug easily.

Lexozz

I guess every 60k+ or so, not sure. The reason mine had to be changed was because the check engine light kept coming on too often. I did get a diagnostic test and it said all the O2 sensors where bad.

additude

What codes did you have that told you it was the sensors?

LexLS

Good writeup and pics .

O2 sensors are at the top of my to do list now but I just got my A/C fixed so I'm gonna have to wait a bit. I thought the wiring harness was on the outside, is that the case for a 91 or is it in the same location as the 95?

Here's a great site that sells O2 sensors cheap, lot's of good info about O2 sensors too: http://oxygensensors.com/

Lexozz

The wire harness is only on the inside for the 2 O2 sensors that are after the cat. As far as the set up for '91 I'm not sure if it is the same, but it should be. If you're underneath looking for it and you see the wire going up into the chassis then I would assume its inside the cabin.