I have a LQ4 with 243 heads and comp 228r 112. I used my original plugs. Now after my LC-1 cut out twice while cruising, Once last night and once today. I think maybe I fouled a plug. Stuck the factory o2 back in and randomly cruising get what feels like a miss and negative spike in spark timing on Hptuners every 4 to 8 seconds. Wondering if maybe I need a different plug and different plug gap since the raise in compression with the 243s and the change of cam. Any suggestions are appreciated. I can upload a log if anyone wants to see it too.

Hope there's no lifter or cam damage since its fresh from Saturday. Being its not so constant and every 4-8 seconds I would think a lobe or lifter would be more constant.

 

After viewing the log little more it is kind of consistent every 4 seconds. I had also changed some idle timing and had matched low and high octane tables as part of a walk through I was going through. Tomorrow flash it back to the previous tune and see if it goes away and was something I caused in the tune.