Blacktop SR20DET spark plugs. misfire or something that im not sure.

[LeroyBrown]

so a year later i change my spark plugs. they were starting to sputter going into boost. well now that i changed them i went with the NGK BKR7EIx-11 6988. me the idiot that i am i gapped iridium sparks plugs to the same specs of the old NGKs. Now that i changed them its having the same problem. i get free gas at my work but i have to put 88 octane. could that be the problem.