Dear billr , yes it is a vvt engine. So maybe one of the cams skip time, it is a timing belt maybe got off timing. IDK.This engine has VVT, correct? That opens up a whole new bunch of possibilities for the valve timing to be off, I'm thinking live-data may be good for catching/reporting problems there, but you would probably need to log all the data for careful analysis, not just a quick look-see at a few parameters.