O2 (Air/Fuel Ratio) Sensor Replacement, Bank 1 - 5VZ-FE, w/ Manual Transmission

doing this now - just unscrew it & it slides right off

 

My connecter was accessible without lifting cover off transmission

 

I got a CEL (code P0031) and was told to test my O2 sensor. I put my multimeter on the two black wires (for the heater?) and got a reading of 13 ohms. On the other two wires (blue and white I believe) I got an open reading. Can someone tell me what exactly this means? I am assuming that I need to replace it. Thanks

 

Welcome to TacomaWorld
I think you're reading Volts not OHMs.
Advanced multimeters will auto switch if the operator is clueless.
Heater resistance should be .8 to .13.
Reading 0 ohms is below .8 which indicates heater circuit failure, short in wiring or sensor relay failure/short.
Replacement B1S1 for your Taco is
DENSO 234-9003
DO NOT BUY IT ON Amazon or eBay
Amazon does offer Genuine Toyota DENSO FROM AMAZON and ones supplied from others. Choose the the genuine supplied by Amazon if you can only buy online. Price varies from $89 to $149.99 don't cheap out on B1S1
https://densoautoparts.com/find-my-part.aspx

 

Thank you and thanks for the response. I was following this video for testing it:
https://m.youtube.com/watch?v=_Kr-c8eBl5E
I am fairy certain I was reading ohms. When I tested black to black I got resistance and when I tested white to blue it read open circuit. I don't know if this provides any new information to you, but I will purchase it OEM if it needs to be replaced. Thanks for the link.

 

Hello, sorry to bump an old thread, but I wanted to get some help with selecting the correct sensor.

I have a 1999 Tacoma SR5 V6 4x4 Manual. Everywhere I look, including the Denso site, all say the

$170 234-9003 Air Fuel Ratio Sensor

234-9003 sensor does not fit my truck. Instead, they all say my truck uses

$53 234-4161 Oxygen Sensor with 15.35” 4-Wire Harness

234-4161 as the upstream O2 sensor.

Can anyone else confirm this as well? Maybe early years of the first gen Tacoma use 234-4161, but later years use 234-9003?

 

Check the emissions sticker under hood. California emissions use A/f .
Federal emissions uses O2 in B1S1
https://densoautoparts.com/find-my-part.aspx

 

Thank you. My truck is fed emissions.

Funny enough, the Denso part site doesn't even list California compliant version of the Tacoma for years 1999 or older. It only lists 2000 and newer for part

$170 234-9003 Air Fuel Ratio Sensor

234-9003.

My truck started throwing PO125 code recently, and when I checked the plug for the b1d1 sensor, it has a broken wire. Hoping to get a new O2 sensor now and replace it this week.

Thank you for helping me with making sure I pickup the correct sensor.

 

Thank you. I was going to start ripping everything from the inside to try to get to the top of the transmission and this confirmed it. What a pain in the ass.

 

Why not repair your wire??

Much cheaper then a new sensor .

I know I would .

 

Thank you this thread made this repair possible for me.

 

Awesome, happy to help.