2nd O2 sensor in 2 years?

[TN22Corps]

I'm getting another "P0136 O2 Sensor Circuit Malfunction" code, the second in two years (to the month). I replaced it the first time with an OE Denso 234-4153. I'm no master mechanic, but I don't think it should need to be replaced every two years.

Until I can get my hands on a fancy OBD scanner, anything else it could be?

 

[ICD]

Did you replace just the sensor or did you also do the harness?

 

[ICD]

What I've seen is even if one sensor is bad while your in replace both and the harness. Guess its pretty common for the harness to be bad and sensor still good.

Did you use OEM?

 

[TN22Corps]

This is what i used:


Denso 234-4153 Oxygen Sensor : Amazon.com : Automotive

 

[ICD]

That could veery well be what's your problem. A lot of those sensor are recommended from a couple different forums to go OEM. Just because they at times are hit and miss. Same is said with know lower ball joint failure. Some aftermarket ones only last a few thousand miles before they wear badly.

Here a OEM parts link to o2 sensors. This site is claimed to be cheaper than most dealers

2000 TOYOTA 4RUNNER Parts - ToyotaPartSales.com

 

[LittleCaesar]

Did you replace both pre and post cat sensors before?

 

[TheDurk]

That could veery well be what's your problem. A lot of those sensor are recommended from a couple different forums to go OEM. Just because they at times are hit and miss. Same is said with know lower ball joint failure. Some aftermarket ones only last a few thousand miles before they wear badly.

Here a OEM parts link to o2 sensors. This site is claimed to be cheaper than most dealers

2000 TOYOTA 4RUNNER Parts - ToyotaPartSales.com

That Denso sensor IS the OE sensor, minus only the red box. I have over 50k on two Amazon supplied Denso O2 sensors and they are fine. Even the code suggests the problem is with the wiring and not the sensor. (P.S. I'm frequently the person on the forums recommending using OE Denso sensors.)

I'd ohm out the wiring before I sank more money into sensors, especially over-priced dealer ones.

 

[TN22Corps]

That's what I thought, that the Denso sensor was the OE. I only replaced the after-cat sensor since that was the one that was throwing a code and when I used a good OBD scanner the front sensor voltage was reading correctly, 0.1-0.9.

I guess I'm on to pick up a multi-meter to check out the wiring. More questions to follow... :shrug:

 

[ICD]

Keep us updated.

 

[TN22Corps]

Update: ended up being a wire that came loose from the harness. Whew.

 

[TheDurk]

Update: ended up being a wire that came loose from the harness. Whew.

What did I tell you??

Congrats on getting the right answer the right way.

 

[TN22Corps]

That's why I keep coming back... If only ya'll knew about older F150s or newer VW diesels, haha.