AFR/O2 Sensor Replacement

[Venz]

Hi there,

I have a 2003 4Runner V6 4x4 with a small issue. I recently failed my emissions test due to a faulty AFR/O2 sensor (OBD code P0136). I took the vehicle to the mechanic to identify which sensor is broken- it is the RH REAR A/F SENSOR.

Around here the part goes for $362, too much for a little sensor. I am thinking of getting a Denso part to replace the faulty part but I have a few questions first:

1. What is the difference between AFR Sensor and O2 Sensor? I'm not sure which part exactly to buy. Densoautoparts.com has the 4 sensors listed as: AFR sensors ($166) upstream L and R, and O2 sensors ($67) downstream L and R. Which one do I need?

2. Where is the sensor I need to replace on my vehicle? The repair looks simple if I can find it.

Thanks for the help!

 

[Nathana92]

Hi there,

I have a 2003 4Runner V6 4x4 with a small issue. I recently failed my emissions test due to a faulty AFR/O2 sensor (OBD code P0136). I took the vehicle to the mechanic to identify which sensor is broken- it is the RH REAR A/F SENSOR.

Around here the part goes for $362, too much for a little sensor. I am thinking of getting a Denso part to replace the faulty part but I have a few questions first:

1. What is the difference between AFR Sensor and O2 Sensor? I'm not sure which part exactly to buy. Densoautoparts.com has the 4 sensors listed as: AFR sensors ($166) upstream L and R, and O2 sensors ($67) downstream L and R. Which one do I need?

2. Where is the sensor I need to replace on my vehicle? The repair looks simple if I can find it.

Thanks for the help!

I have the same code right now. It's bank 1 sensor 2, so it's an O2 sensor. Meaning it's the one after that catalytic converter on the driver side. So you need the L O2 sensor for $67.

 

[BOSMECH]

Get it off the internet and use Denso.
Its not a bad job since it is the one after the CAT just make sure you use a thread chaser before you install the new one with anti-seize compound.

 

[oljedi11950]

A/F sensor

There are a total of 4 , 2 before cat , 2 after these are cheaper on amazon about 70$ , these are O2 sensore the before are air/fuel more $ , I got mine on amazon for 120 something , haven't installed yet these could be BI^%h make sure you have right tool . As bosmech said use all his tips . The after cat o2 are real easy

 

[Venz]

Get it off the internet and use Denso.
Its not a bad job since it is the one after the CAT just make sure you use a thread chaser before you install the new one with anti-seize compound.

Thanks for the advice! What is a thread chaser?

And will the part come with anti-seize compound?

 

[oljedi11950]

i used PBlaster since replacing them ,rust, let it soak & yes they come with small tubes of anti-seize .

 

[Nathana92]

Just ordered Denso 234-4261 Oxygen Sensor from amazon for $51.85. I'll post up results...Much better than the $180 the dealership quoted me. I'll buy and replace 4 of these before I pay that kind of mark up.

 

[Venz]

Ordered O2 Sensors

Just order both downstream (after cat) O2 sensors.
Denso O2 sensors 4804/4805
Will get installed and post results.

 

[oljedi11950]

Just a heads up URDUSA has all the O2 sensors by yr ! That's how I knew the right one's to order .

 

[earthrealm]

when i changed mine on the rav4..it was a lot easier spraying wd 40 days b4 the actual change..and also doing the job when the engine is warm, o2 socket wrench - piece of cake

 

[Venz]

Issue resolved

I received the ordered parts in the mail, got them installed, engine light disappeared and I passed emissions test, success!!
The silly VSC TRAC/TRAC OFF lights are still on, but I think this is common and not sure if I can get rid of it without OBD machine thingy, anyone else have any thoughts or suggestions for the VSC codes that remain?
Thanks everyone for commenting on my original post.

 

[earthrealm]

TRied dosconnecting ur battery?..it might reset the vsc trac lights.........

 

[Jables]

Vsc and trac

I also have an 03 and from what I've researched there is something different with the computer programming that was later corrected if your abs light is not on u will need to do a 0 point calibration to reset your lights u can buy a little adapter or make a jumper wire on a level service there's 2 pins in your obd2 port you have to contact 3 times and it will re calibrate and reset your lights but frow what I've read it can't be reset with a normal reader there's a few good vids on u tube that can walk you through doesn't look to bad if your not half blind like me