Should the check engine light go off by its self?
Mine came on and showed a p0158 code. After it was
cleared the light came back on after a 100 miles or so.
i did not check it, I just assumed it was the same. After
a couple of hundred miles the check engine went off by
it self. I thought it would stay on until cleared.

Mike

 

If the situation that caused the fault is no longer present, the fault will clear on its own. It takes a few start cycles, but it will go off. I think the code will still be stored, though

 

So, if someone yells fire, how long do you wait till you get out?????????????????
A check engine light is there for a reason, did you replace that failing 02 sensor, how many miles on your truck?
You are going to find out the hard way $$$$$$$$$$$$$$ that you don't pretend there is no problem.