everyone needs to stop interchanging the letter O with the number 0 in mask names.

masks are hex, there's no letter "O" in hexidecimal

this will help you when searching for information about...

if your o2 voltage is below switch point at anything but cruise or closed loop, you're lean. need to add some more fuel.

maybe spark isnt your problem at all?

park brake or transmission park/neutral?

they're very different things.

i've never seen an oldschool GM ecm where the park brake switch does anything

park/neutral or shift position switch...

if it's knocking definitely remove some spark advance. if it still knocks there remove some more. if it still doesnt' go away you might have false knock (mechanical noise or knock filter no good for...

trimalyzer does have a knock analyzer built into it but knock analysis is as good as it gets, no tool will automatically tune spark (too dangerous, needs a practiced hand)

spark advance is tricky...