DIY : Downstream Oxygen O2 Sensor replacement

[Maim Menu]

Have a P0141 Heated Oxygen Sensor Circuit Malfunction (bak 1, sensoe 2). I do not know for how long I've been running the car with that particular code since the CEL has been on for a year with P0446 but didn't want to go with a defective 02 sensor for too long so started thinking about doing it right away. I'm less of a car noob everyday.

The hardest part of the job was to remove the old sensor from the exhaust. My car is a '98 Camry 5sfe with 290 000 Kilometers, non california model.

Things you will need :




1.A Torch : It will be MUCH easier to remove it by heating the base (where the sensor screws in) a lot. I started working on the car without a torch, just by idling until exhaust was hot and tried to unscrew, then gave up and went out to buy one, old sensor was out half an hour later.

2.02 sensor socket : You could easily go without one. You could use an open 22 millimeter wrench or a vise grip. The 02 sensor socket damaged the old sensor, and my self pride along the way. I bough a pair of big Vise Grip and a torch to remedy the problem, worked like a CHARM. The socket was useful to gently screw the new sensor back in though, so it was good to have one anyway

3.Ratchet wrench : I don't know wich size, it wasn't specified, but it's the biggest one in my kit.

4.Vise Grip wrench : I used it to unscrew the old screwed up sensor. I think this would work better than an open 22 millimeter wrench since you don't care about damaging it at that point, although you're obviously not gonna use a vise grip to put the new one back in.

5.Lube : heat/fire resistant penetrating oil

6.And of course, beer. To ease off the possible frustration of the first step.

7.Not shown on picture (sorry) : New 02 sensor, paid 293$ CDN at dealer. I think people in U.S.A. get them for cheaper though.


The process :

1 : Lube/heat/repeat until the old sensor comes off. What you want to do is heat around the base, and the base itself to expand the threads. Don't heat the sensor itself, that'll do no good. Believe me, I didn't have a torch when I started and this would've been impossible for me. I'm not a big guy so muscle comes in the form of neighbours or roomates. So fuck it, get a torch. I used a vise grip to break it free and unscrew it because the 02 sensor socket damaged the sensor's "bolt"




2. I removed the front driver seat. A lot of people say you can access the connector from underneath it, through the hole in the carpet where the air ducts are, but I don't like working on things I can't see, so I went the noob way. Haynes manual says not to disconnect the seatbelt safety system connector, or your airbag light could come on, so I called several local Toyota dealers and spoke to techs that told me it was not a problem as long as the ignition key wasn't in. Now that I think of it, I forgot to disconnect the battery. There's a black plastic clip holding the wire underneath the seat, stick your fingernail in the crack on the backside of it and it will clip open so you can let the wire free, then Disconnect it. Remove the 4 bolts holding down the seat and take it out. Here's what that connector looks like :




3.Pull the carpet back starting from behind the pedals, it comes off easily, you have to carefully pull the center console's plastic "flap" towards you to slide the carpet out of it until you can see the connector and work on it properly. It's disconnected on this picture, the female part of the connector was held on to the floor by some kind of clip that you don't need to undo anyway. I pulled the rubber pigtail inside of the car (it is actually pulled in on the following picture), then snaked it back out along with the connector. The old sensor was out! I thought about completely destroying it with a hammer and the torch while laughing out hysterically but held on to myself.




4. Carefully screw the new sensor in, I used the 02 sensor Socket and my ratchet for that. I didn't screw it in too tight. Until the metal ring at the base of it was seating and it was harder to turn, I locked it in securely and was done. Slide the connector through the hole in the floor and snake the rubber pigtail back in the car then reconnect and properly seat the rubber pigtail against the hole. Easy, but hard to explain, you would understand just by looking at it though. Replace carpet properly. Again be careflul not to rip it up, just slide it back underneath the plastic flap of the center console.




5. Screw the seat back int and disconnect your battery to reset computer and codes. I used a sensor I got on ebay to do that.


You're done, I will report back in about a week to let you know if P0141 came back.

If you got any questions or comments you are welcome. I'm still pretty much a noob at cars by the way, so any tips or additions are also welcome.

EDIT : The code DID NOT come back.

[dc_98_cam]

Interesting ...
Generally, when this procedure is described, an anti-seize compound is recommended for the threads prior to re-assembly .... so that it won't require so much effort to unscrew in the future.
Something along the line of the following item:
http://news.thomasnet.com/fullstory/28214/1083
... Sounds like there wasn't any of this compound applied during the original installation.

[Maim Menu]

If you use a new sensor it will already have anti seize on it, but my understanding is that it doesn't make much of a difference.

[dc_98_cam]

"If you use a new sensor it will already have anti seize on it, but my understanding is that it doesn't make much of a difference."

.... When mine goes out, I might try using 'extra' anti-seize, in addition to that applied by the manufacturer.
.... Could be that high temperature exhaust duty, after so many miles, is just too much for any thread compound, other than 'rust', to be effective.

[Maim Menu]

I went downtown tonight it's national day here. I just got back and scanned my car again, I only have good ol' P0446 on pending status so it didn't trip the CEL yet, but P0141 did not come back, and the O2 sensors routine checks were completed according to my scanners so all is good for now. Car is running a bit better too.

[213solider]

you need a coors light bottle afterward!!! lol

[Albuynp Ryeno]

I am having a hell of a lot trouble removing mine, you twist to toward the end of the car right?

[Hajoca]

Counter clockwise, correct?

I had to do the same, only I was able to get the under seat connector from rear seat floor.

Alb... I hope you have a garage, I waited till spring 2007 to change mine.

[Maim Menu]

Yes, you twist towards the end of the car, or counter clockwise.

They are a b*tch to remove usually, Heat the base a lot, until you can see with your eyes that the thing is really hot. Mine wasn't RED hot, but you could tell it was really really hot. Don't heat the sensor itself, just the base. Heat/lube/try/heat/lube/try/heat/lube/try. It has to come out at some point.

Good luck!

[Hajoca]

if sensor is fouled, you do not need to be gentle, break it off to save the wire harness, boot etc and use socket and breaker bar, etc.

[Maim Menu]

Yeah, if the actual sensor is not good anymore, forget about the fancy O2 socket, whip out the vise grips and a pair of gloves or a piece of cloth to put over the handle and let it rip.

[snigma]

I know, old thread--but I just did mine and thought i'd add to help out:

'98 Camry, 5S-FE, 98k miles.

1.) Instead of using the torch and vise grip, I used a 14" Pipe Wrench. Put it over the bolt (where your socket/vise grip would go) and go at it. It was hard, but I sprayed some WD-40 a couple times, and it came off. It helps if you have a longer handle (more torque), so 14"+ would probably be even easier.

2.) It is not necessary to take off the seat (although I did). You can feel around and figure out the rubber grommet as well as the plug. Push the seat forward and use a flash light.

3.) I got the BOSCH brand o2 sensor (OE type), it comes with the rubber grommet, the wire clip (that clips on outside the car). In this way, it was a easy job--no need to save the old harness or anything like that.

4,) I put the new sensor on with an adjustable wrench.

[xtremeskier97]

Originally Posted by LaurenShields

Bosch = Botched

OEM Denso is much better, you'll see in a few thousand miles.

+1

[Maim Menu]

Originally Posted by snigma

I know, old thread--but I just did mine and thought i'd add to help out:

'98 Camry, 5S-FE, 98k miles.

1.) Instead of using the torch and vise grip, I used a 14" Pipe Wrench. Put it over the bolt (where your socket/vise grip would go) and go at it. It was hard, but I sprayed some WD-40 a couple times, and it came off. It helps if you have a longer handle (more torque), so 14"+ would probably be even easier.

2.) It is not necessary to take off the seat (although I did). You can feel around and figure out the rubber grommet as well as the plug. Push the seat forward and use a flash light.

3.) I got the BOSCH brand o2 sensor (OE type), it comes with the rubber grommet, the wire clip (that clips on outside the car). In this way, it was a easy job--no need to save the old harness or anything like that.

4,) I put the new sensor on with an adjustable wrench.

I remember coming across a thread about this problem a while back and the guy used Bosch sensors, the code came back so he threw money elsewhere trying to fix other related parts until he finally tried a dealership sensor that worked on first try. If it worked for you it's pretty cool cause you probably saved a good amount of cash, but I only use dealer parts...

[fenixus]

so wait, this was done on gen3 or 4 ? do you have exhaust under the driver side ?
mine on gen1 solara (gen4 camry california specs) is on passenger side, and i think i'm supposed to look under the passenger seat for the o2 connector ...

trying to plan this task up correctly while waiting for a new NTK o2 sensor for rear...