random/multiple misfire code
 

engine running super rough but not all the time. engine light is always on but when it's damp out, the light flashes.
o2 sensor gone but has been for quite some time, engine troubles just began recently.
mass air sensor and 6 new plugs installed the other day, no difference.
all wiring looks good, no visible shorts/grounds.
sometimes only a slight drop in power (maybe 1 cyl) other times almost gutless (3 or more cyl).
any ideas?