Hi. My check engine light came on, and it turned out code

P0135, O2 Sensor Heater Circuit, 02 Bank 1, Sensor 1

Which sensor is this, and how/where do I access it from? I did a quick search for O2 sensors online and there's several dozen of them. Which sensor do I need?

When the car is left idling, either in park, or in drive but stopped, the rpms dip below 500 rpm. probably closer to 300. Just so happened that the check engine light came on around the same time. Would these two events be linked? Could it be a PCV valve? I haven't done much work on the Civic really, so I'm not too familiar w/ it.

Thanks in advance for the advice!

Adam

 

It's the primary O2 sensor (before the cat). Fix the code and go from there.

 

well as much as the car idling low i wouldnt worry about it as long as the motor stays running.
but if it tries to die i would just check how much slack you have on the throttle body cable on the motor. and if its to much slack in the metal core then simply tighten up the throttle body cable mount nuts to tighten up the cable a bit.

 

Addiction, a too slack throttle cable won't cause a low idle. The throttle stop screw sets the minimal amount that the throttle plate will close.