Is that antiseize on the threads? If so, what did you use?
Also, misfire tables are under engine diag
View attachment 482876
View attachment 482878
If they've been set up like seen here - 32767 it basically nullifies them - my 98 LS is known for bad readings so someone along the line nullified them.
The anti seize on the O2 is stuff that comes with the O2's
My engine diagnostic menu looks like this.