Civic LX 2007 ~115K with a cel P0135

I have replaced the upstream O2 sensor twice now but the cel came back on. After the first replacement and the reappearance of the P0135, I check the resistance on the heater circuit. It was 3.7 ohms. My research indicated it should be between 10 - 40 ohms. I think I got those numbers in the forum or one like it. I got a replacement from the parts store yesterday, installed, cleared codes, re-read, no P0135 and bang it's back this morning.

What am I missing here????

Troutwater

 

...besides a sense of humor.

 

Did you check resistance of new unit before installation? If the value of new one is the same as your old one and if the correct value shall be 10-40, which seems a lot of range to me, for sure, you will get the same code,,,,,.

I am just saying this without knowing your car's system, so I guess, it has no value,,,,,.

 

I was so happy that the parts store gave me a new one I didn't bother to check it before installation.

If it does turn out to be a resistance of 10 - 40 ohms in this newest one. Then is it possible that the replacement part does not have suitable specs that the original part had????

Guess I need a spec guide.