O2 Senor

[Joshua]

Has anybody notice that the O2 senor will get warm to the touch with the engine off and the key in the on position? Then again not sure if its my O2 senor or my A/F senor. Is this normal? I was verifying if my roll over valve was working in my garage and right away I felt it getting warm

 

[cannondale27]

That's normal. Is a heater circuit on it so it works properly.

 

[Joshua]

Thanks