How To Test Oxygen Sensor

My check engine light is on and the diagnostic codes indicate a problem with the oxygen sensor. The thing is all this happened after I paid someone to do what I now think is a mediocre job replacing the valve cover because it was leaking oil.

Since that’s happened I had to replace the alternator and also the traction control error light is always illuminated. I think it’s possible that it’s not the oxygen sensor but either a short or an open somewhere in the wiring from lousy work. How do I test this oxygen sensor and associated wiring? Like if I were to remove the connector for the oxygen sensor, what voltage and/or resistance should I be reading across the sensor and what voltage and/or resistance should I be reading across the wire ran to the sensor?

 

What year and engine is your truck and what code number(s) are you getting?

 

You should connect OBD scanner to the DLC and read the lambda and voltages through startup and in closed loop mode.

 

It’s a 2009 with a 2.7 L engine. I don’t remember the code but I’m just wondering how to test the oxygen sensor to tell if it’s really what the problem is.