I had my evo 9 tune on denso ikh24 one step colder spark plug. i was checking my spark plug but broke 3 of 4 plugs. dealership tighten down too much. i have a set of oem laser ngk spark plugs. will changing to the oem ngk effect my afr and tune?

 

no

 

Spark plugs will not affect your tune but they could affect how well your car runs based on the gap for example.

I wouldnt be concerned with that right now but what I would be concerned with is how 3 of your 4 plugs are broken. Can you elaborate on that because broken plugs could signify much more serious issues...