Is there a short cut in getting the downstream O2 sensor off the Cat? I have penetrating oil and it wont budge. Got a O2 sensor tool, cant seem to loosen it. am i stuck and have to replace the cat? Any help would be greatly appreciated.

 

Let the engine run about five minutes.

 

yeah, try loosening it when it is red Hot, just wear glove and becareful.

 

Thanks guys worked like a champ. How cOmmon is it that 3rd party sensors fail/don't work and have to replace with Mopar?

 

For Chrysler, I am going to say maybe 1 out of 5.
For some Import like Honda and Toyota, 9 out of 10. Sensors for engine management, I highly recommend to go OEM just to save some headaches.