Plug wires
 

1992 Loyale

I looked at them in the dark with engine running and saw some arcing, not as much as on other vehicles but several spots.

How bad is it and do they need to be replaced?

How many miles do you have on those wires? if you don't know.. Replace them.

I don't know the mileage. I would guess at least 30,000 and possibly as high as 178K if they have never been changed.

change 'em.

If they are arcing you need to change them