Just wondering if any body can tell me more in detail what 02 censor that. I replaced the highest one on the y pipe that sticks out to the right if your facing the car. Then reset the ecu and came back. Thanks ahead of time guys.

 

0503
Diagnostic Trouble Code 0503 indicates a problem with the front Oxygen Sensor on the right cylinder bank. The right bank is also called the rear bank. It is cylinders 1,3,5. A normal signal sweeps back and forth between 0.2 volts and 0.8 volts. This malfunction was detected when the Engine Control Module received a signal from the sensor which was a constant value of approximately 0.3 volts.

Possible causes include ...
- Harness or connectors (the sensor circuit is open or shorted).
- Defective Oxygen Sensor

this is for the second o2 sensor(the middle of 3 total) in the y-pipe. the one you replaced is called the Front Left O2 Sensor, the one you have to replace is the Front Right. same part as the one you replaced. they are about $60 at oxygensensors.com

 

Just got my order from oxygensensors.com - those guys are good. I called my order in just to be sure.

 

If you still have the sensor that you replaced - i.e the old one, you can use that to replace the one that is really bad (the front right - closest to the firewall on the y-pipe).