I have a 2006 with GM stage 2 and K&N CAI? Do I need plugs. Its an obvious question since I don't have anyway to watch the engine stats as of yet. I am thinking about getting the HP Tuners or one of them handy dandy guages, but I don't yet. Just curious since I am still getting a ton of black stuff out the tail pipe...seems a bit worse with stage 2 installed. Any input would be greatly appreciated.
