I replaced the oring.

After I fit in the oring and tightened the bolt, I can feel maybe 1/3 of a fingernails width between the sensor and the engine. I turned on the engine and Its not leaking now... Should I be worried? Is the new oring too fat? mm

 

If it is torqued properly and not leaking you are good to go. Check once and a while to make sure.. I can't say how they are normally.

 

Did you lube the Oring before installing? If not it may not let you slide it in. I suggest pulling it out and reinstall it.