bigfoot89

Hi,
I would like to ask some questions about O2 sensor. About 2 months ago, the engine check turned on on my CRV 2004. The code is P0135. I bought an universal O2 sensor ( about 37usd) and replace it. The engine does not turn off. I go to Autozone again to ask them to erase the code. They said they can not do it anymore due to the new policy. Therefore I bought my own code reader. And when I obtain the code, it is P2025.
I think the problem is still O2 sensor.
Could you please tell me which one is upstream/ Downstream? Before catalyst or after catalyst?
I have a picture of my 2 o2 sensor. Please refer to this picture.

Thank you so much.
Also, beside the engine check, there is "SRS" light turn on. Read color. Do you know what is the problem?

Thanks for any kind of advise. Have a great day.

Harry John

the oxygen sensor can be tested for response rate but you in all probability don't have the tools to do the test.

On the 2004 CRV the on-board diagnostic system tests both the O2 sensor heater circuit and the operation of the O2 sensor every time the vehicle is driven. If there were a problem with the sensor the check engine light would be turned on by the OBD II system.

kyden

p2025 is an evap code. has nothing to do with your o2 sensor.