Hello,
I have 2007 saturn vue 6 cylinder .error code check engine light on P0135, it's O2 sensor bank 1 sensor 1, I took sensor out clean and check meter ohm about 4.5, and reset read code, after turn on engine about 10 minutes error code P0135 come on again, sometime engine light come off and on again, can someone help me out
Thank you very much

 

The code is for a heater circuit malfunction on bank one sensor one.

I would check the connector end of the sensor wiring and where it plugs in for any damage. I would then check the entire length of wiring from the connector to the sensor itself for damage. If none is found, the issue is probably inside the sensor itself and the sensor will require replacement.

The fact that the SES light goes on and off indicates to me that it is likely a damaged wire or connection. This is most often inside the sensor base and there's not much you can do about it. The ECM must keep a very small current running through the heater circuit at all times and monitor it in order to ensure the heater circuit is functional. I say this because the purpose of the heater is to get the oxygen sensor up to temperature faster at startup so that it can control the emissions from the engine faster. Under normal driving conditions, it just sits there but is exposed to very high heat which over time will damage many things. If it was an O2 sensor heater fuse, the issue would be constant though I suppose it's possible the fuse has corrosion on it and is bumping around making and breaking contact so check that too

 

Thank you very much I will order sensor and replace first