2002 1500 reg cab 4x4. Got this code yesterday after the CEL light came on and I did the key dance. Says it is the O2 Sensor 1/2 Heater Circuit Low. So what exactly does that mean? And which O2 sensor do I need to chang? From what I have read there are multiple ones. Thanks, Paul

 

This is a simple fix, the code is telling you that the driver's side, post cat O2 sensor is NOT giving a signal to the PCM after the vehicle has reached operating temperature and switches to closed loop.

Replace the sensor...

 

So i just need to replace it?

 

$25 at Autozone or the dealer of your choice. Reset the PCM after swapping it out

 

how do you rest the PCM?

 

Disconnect the battery posts for 30+ seconds