Originally Posted by
MugenR
I had this happen to me when I went from Iridium plugs to NGK's. When i went back to iridiums everything went back to normal.
Ive heard a thousand variations of this although most say the iridiums make it worse. I think its whatever you had when you were tuned is what you need to stick with. In my case I had a stock plugs in there and thats what I have now and it seems to be better than iridiums or platinums.
I may try one step colder but I dont think that will work either.