I recently got my car tuned, put on a 3.5 pulley, had new MSD 8.5 wires, and brand new tr6 plugs gaped at .30. but for some reason between 7-11 pounds of boost. my car starts to misfiring and almost boggs down, the SES light flashes for a good 30 seconds. when i went back to where i got it tuned, he used the tuning software and i made the misfire happen, and he said it was misfiring (6th cylinder) he replaced the plug, and checked the wire, and that swapped the coils, to see if it was an issue with them. and it still did it. any idea what else to check?