02 sensor location and replacement

Hi jon,

There is a Chinese saying, every cent is worth its quality. Usability is not a problem but reliability is a question mark.

There are 2 sensors, located before and after the catalytic converter on the exhaust system under the vehicle

Here's a guide on how to replace the oxygen sensor

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

See the pictures below for locations

Hi Experts,

Check Engine light is on in 2004 Honda CRV. Went to Autozone and they read the code and provided the following information

************************************

Troubleshooting : P0134
OEM Brand : Honda

Definition
A/F Sensor 1 heater System Malfunction
Probable Cause
- Open or Short circuit Condition
- Poor Electrical Connection
- Faulty A/F Sensor 1


TroubleShooting : P0135
OEM Brand : Honda

Definition
A/F Sensor 1 heater System Malfunction
Probable Cause
-Open or Short Circuit Condition
-Poor Electrical Connection
-Faulty A/F Sensor 1
***********************************

It seems the issue is with Oxygen Sensor when I looked at the Internet.
I have tried to shop around in Internet and found there are 2 types of Oxygen sensors and I am confused which one to buy.

My question here is,

Do I need to replace the Oxygen Sensor?
If yes which one I need to buy (the front one or the back one), Please provide the part number or some specification to purchase. People are advising me to buy the Denso one.

Can I replace that myself. Do I need to get Under the car for doing that or simply opening the hood will do?
Please let me know your valuable answers.

Hi deepak05,

Thank you for the donation.

For O2 sensor replacement, you would need to get under the vehicle to replace it. see diagram for location. The sensors tends to get stuck at times and might strip the threads. Some rust remover sprayed onto the threaded area and allowed to soak would help. Try yo do it with a hot exhaust to avoid it seizing while unloosening.

Before replacement, it would be best to perform diagnostics and since P0135 is present, ohming out the sensor heated circuit would enable you to test if the sensor is faulty. The 2 black wire is the hated circuit and it should have between 1.5 ohms cold and 4.5 to 5 ohms when hot.

The sensor that is faulty is the front one.

OEM is the recommended one and ND is the OEM supplier so should be the preferred choice if you are not going for OEM.

Hi,

COuld you please give me the diagram to locate the Oxygen sensor?

Inorder to check the sensor, I just need a multi meter correct? I will purchase one and do the check

Deepak

Sorry for the mistake. I was suppposed to attach a diagram and seem to miss it out after answering the question.

If you need further diagnositc procedures, I can get the file for you.

Thank you so much your help. Please send me those diagnostic procedure file.

After getting the reply from you, I am confident that I can do that.

Could you suggest me a good Multi meter too.

Thanks in advance

I have sent the files.

Our parts store do have rather good multitesters. Check them out with the links afer my signature.

I took my CR-V to auto zone when the engine light lit up to see what the problem was. The codes that he retrieved said that there was a problem with the O2 sensor in the car. I can not seem to locate the sensor or sensors if there are more than one. The Haynes manual I have is a little vague on the location so here I am. Thanks in advance.

Hi mpendergast912, A = primary O2 sensor. B = secondary O2 sensor. C = Catalytic converter.

Where is the oxygen sensor #2 located and is there anything I should know b4 replacing it?

Hi kelly gorans,

The #2 HO2S is plugged into the rear end of the catalytic converter.

You should check if the catalytic converter and the wiring circuit is ok before replacing the sensor.

Check engine light had two codes originally, P1166 & P0134. Installed Bosch Universal sensor in Bank1 sensor 1 location which is one closest to engine I think. Reset by disconnecting battery cable. Check engine light went off for few seconds then came back on. Retest showed Check engine light had one code, P0134. Honda dealer thinks their sensors (NKG) have a wider range and dont trip as fast as replacement(Bosch). what do I do next?

Its an AF sensor and not an o2 sensor
if you are using the universal o2 sensor it would fit but will not do the job
have to order by application

need manual CHECK IT @
https://www.2carpros.com/kpages/auto_repair_manuals.htm
_________________

Electrical problem
2004 Honda CRV Automatic 88000 miles
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my question is does anyone know where i could locate my 02 sensor in my 2004 honda crv and when i locate it is it a big job replacing it?
thank you for your help in the previous questions

Hi marbella7,

The O2 sensor is plugged into the exhaust under just before the catalytic converter.

You need a special tool to remove it and quite often it tends to jam up bad, shearing the threads when removing. A little rust remover before removing is recommended but no guarantee.

The check engine light came on and the OBDII code reader stated the O2 sensor has no activity, code P0134. I found out that the CRV has a front and rear O2 sensor. How do I go about finding out which sensor is the bad one? Thank you!

Hi sirjr,

Thank you for the donation.

P0134 = bank 1
Bank 1 = Front sensor ie. before the catalytic converter.

Bank 2 = Rear sensor ie. after the catalytic converter.

Replaced #1 02 sensor. check engine light still comes on code po131 no activity this a 02 crv

I show a P0131 as oxygen sensor low voltage. A low voltage code is different than no activity. Low voltage means the vehicle is running lean (too much air or too little fuel). If the code is actually a low voltage code, then I would look for a vacuum leak, or low fuel pressure.

That code doesn't even appear to be one that car is programmed for. I would try a different code reader because that code doesn't apply to your car.

Recently I changed my 2002 Honda CR-V catalytic converter and replaced it for about $550. The check engine light came back on again after a couple of months. I took it to another dealer and was told I need to change the oxygen sensor (code:P1166). Shouldn't the first dealer detected the problem in the first time? Did he fail to note the real problem (the oxygen sensor) and change the wrong part?
Your professional advise is highly appreciated.

Honestly, I would need to know what codes he found at the first shop. There is a chance that the O2 sensor went bad after the fact. By any chance do you have the original trouble code that was found?

one month ago, i had a yellow light with the shape of the engine. i took my car for check up, the technician told me that i have a problem with the o2 sensor he reseted the light and he tolld me i can keep driving my car untill i feel that its fuel consumption is higher than normal then i have to change the o2 sensor. the light now appears for 2 or 3 days, after it went off for 2 or 3 days. please advice me what to do and what are the problems that i might face if i kept driving my car without changing the o2 sensor.

https://www.2carpros.com/articles/how-an-oxygen-sensor-works


That is an article explaining how oxygen sensors work. If your oxygen sensor is reading improperly you will suffer an increase in fuel consumption which can also warm your engine. Fuel contaminates engine oil, may damage catalytic converters as well. The code may of been for the heater circuit as well, which just indicates that your oxygen sensor is not heating up fast enough according to OE spec.

How can I instal front oxygen sensor by myself. I already bought the part.
Thanks a lot!

just unscrew it and unplug the electrical connections and reverse procedure for installation

thanks for using 2CarPros.com!