Signs of a bad opti ?

[95z28]

Past few days car has been actin up a bit sputters a bit kinda only in the higher rpm ranges and never under like 4mph. i was figurin it was a mis fire but then i rememberd about the good ol optispark . . .

[93BlackZ28]

i replaced mine a about a half a year ago. My car would cut out at high rpm and blow black smoke then i took it to the shop and they drove it and it died so $800 later i had my car back!