replace upstream oxygen or air/fuel sensors (1mz-fe)

[bassthrive]

For gen1-1.5 with the V6 engine [california and federal]

Time to finish, 30 minutes.

Tools required...



Run the car for about 5 minutes if cold. Give the sensor threads a shot of penetrating lube. Let's do the rear (firewall) sensor first. Here is the location.



Unclip the sensor (not shown, just follow the wire up - it is under the intake plenum). Slide the removal tool over the sensor first, then attach your socket and push down on the wrench, i.e. counterclockwise. Once you break it free, the sensor is very easy to unscrew by hand.



Now the front (radiator). This is the easy one. Unclip the sensor from the harness and where a black clip holds its wire on the transmission dipstick tube. Loosen it with the tool and remove.



Installation is simply the reverse. Apply anti-seize to the threads before installation. Here is a comparison of my 100k mile sensors.



I did this all without lifting the car. Reaching down for the hot firewall sensor can be painful so I got creative with an old t-shirt and tape...

[Gregtrd]

im pretty sure you got O2 sensors and your car is cali. spec, the air/fuel sensors are an a no precat fed. spec solara.

[bassthrive]

im pretty sure you got O2 sensors and your car is cali. spec, the air/fuel sensors are an a no precat fed. spec solara.

i'm pretty sure you got it backwards

oxygen sensors = federal
air/fuel sensors = cali

they do look similar

[aleki2424]

im pretty sure you got O2 sensors and your car is cali. spec, the air/fuel sensors are an a no precat fed. spec solara.

i'm pretty sure you got it backwards

oxygen sensors = federal
air/fuel sensors = cali

they do look similar

yep. And very easily confused,

[Dawgz]

Cali spec = A/F sensors

Federal = O2 sensors, Bassthrive is correct.

[Chinky420]

but the important thing for this DIY is that they're located in the same place

[Jakecallun20]

Thx for the write up, I may be doing this soon Damn CEL

[r0yalty]

Thanks so much for this thread! nothing beats DIY!

[pbartosz]

great tutorial.
I found it difficult to get to the sensor near the firewall so I tried to find an angle from under the car and I couldnt find anything better. So I tried again from on top and I took out the plastic air manifold and was able to reach the darn sensor 1.

My problem now is I can't get the new sensor to thread back into the hole. It seems like I stripped the inside threads somehow. I used a big box wrench and with leverage, and PB penetrator I was able to turn it loose. Has anyone ran into this issue? I heard I need to get a tap and chaser to try and rethread the inside of the O2 sensor hole.

Any suggestions?

[pbartosz]

so... I tried again and this time I heated the car up to regular operating temp. the new oxygen sensor screwed in smoothly. The problem was that the hole is smaller when the exhaust manifold is cooler and expands when it gets hot.

Next problem is the connector clip did not fit. I soon realized that I have a CALI emissions spec vehicle and this O2 sensor will do me no good.

THE END

anyone need a new WALKER O2 sensor never used. 100$? OBO

[nnnyyy]

I just wanted to say thanks for the write up.

I had a P1135 CEL come up at 130K mi. Referring to this post, I decided to try to fix it myself. I purchased the genuine a/f sensor online along with the offset crows foot socket, followed your instructions and was done in 15 minutes.

Few notes:
P1135 is Bank 1 Sensor 1 (B1S1). It is the sensor closest to the firewall, not the one next to the radiator, and not the one after the cat.
On my '99 Cali spec, The original part number was 89467-41020. It has since been replaced with the updated 89467-41021. Some dealers refer to this as the 'right' sensor (as opposed to the 'left').

All the work should be done from the driver's side. It looks closer to the passenger side but there isn't much room. Just lean over the fender and snake your arm around. I wasted a bit of time trying from the passenger side.

Remember to work on a warm/hot engine. It is much easier to remove and install the sensor.

[lexmex]

This came in quite handy for a friend of mine with a Solara who just took it south of the border to Monterrey (he's there for a year).

[mazen222]

so... I tried again and this time I heated the car up to regular operating temp. the new oxygen sensor screwed in smoothly. The problem was that the hole is smaller when the exhaust manifold is cooler and expands when it gets hot.

Next problem is the connector clip did not fit. I soon realized that I have a CALI emissions spec vehicle and this O2 sensor will do me no good.

THE END

anyone need a new WALKER O2 sensor never used. 100$? OBO

Well, i think i have the same problem as you... i bought an O2 sensor but i get the CEL back after 30 min of driving... is it possible i got the one you were supposed to get and vice versa?

thats the one i have on my car:
http://cgi.ebay.ca/Front-Lambda-Sensor- ... 25568f49fb

i'm front canada montreal... i have no idea whats the cali or federal specs.

if it is the case, we can do an exchange if u want