P0135 Error Code - 2nd time in a little over a year

[JeffinSeattle]

I changed the Bank 1 Sensor 1 O2 Sensor a little over a year ago and yesterday for the same error code after checking with the Scanner when check engine light went on.

Its a 2000 Lexus LX470 with 116,000 miles on it.

Any suggestions? Change the sensor again?

 

[SkiLyft]

Interesting: my error code for the upstream sensors was coded as P0155 - heater core... Or something like that... What else did the code reader spit out?

 

[JeffinSeattle]

That was it. P0135 O2 Sensor Heater Circuit Bank 1 Sensor 1

 

[staggrlee]

That was it. P0135 O2 Sensor Heater Circuit Bank 1 Sensor 1

I had a P0141 a couple weeks ago. Also an O2 sensor code. I reset the CEL and it hasn't come back. I replaced all the sensors with Denso replacements less than a year ago. They can throw a transient error but don't auto reset. I'd just reset and see if it comes back.

 

[97 FZJ80]

The older Toyotas required Denso O2 sensor, it will often fault out on the heater if other brands of O2 sensors are used.

 

[JeffinSeattle]

Reset the CEL and unfortunately a day later the light came back on...UGH

Should I replace again? Or is this a sign of a larger issue?

 

[mrbigboy]

Double check your ground wires, especially the main ground off the ECM.
I had a similar issue with my Tacoma awhile ago. Long story and $500 in parts later it was a loose ground wire.......

 

[staggrlee]

Were they Denso? If not, then yes.

It's possible to test an O2 sensor with a multi-meter but you need to know what the acceptable voltage range is for the sensor/car. It may be in the svc. manual or somewhere here on the forum.

 

[JeffinSeattle]

So if I do replace no question about it replace with denso?

 

[JeffinSeattle]

Just checked on amazon...I replaced it with this one

Denso 234-4169 Oxygen Sensor

 

[staggrlee]

Diagnosing/testing O2 sensor in post #12 here: https://forum.ih8mud.com/threads/o2-sensors.443520/#post-6196439