I just removed my o2 sensor on my 95 taco yesterday and stripped the nuts like you wouldn't believe. they were very difficult to remove, even when saturated with liquid wrench. probably the high heat of the exhaust system and rust. the studs stayed on fine (on my truck at least).
I'm about to head to the dealership to get some new fasteners. $3 a nut, that's nuts.
T.B.
I saw the post above about sensors, so I don't need advice about finding > replacements.
>
> I expect that I will have to replace mine too, as I am getting check engine
> messages. I have looked at it and am afraid to touch the fasteners holding
> it to the exhaust pipe. The studs and nuts are BADLY corroded/oxidized. Do
> these studs have a tendency to shear off when being disassembled in this
> state? Or was some sort of long-life anti-seize used in the assembly? I
> have visions of having to replace the studs or the entire pipe when I get
> into it. Is there a preferred fix when the studs break off?
>
> Thank you
>
> Jim Andrus