Firstly, just got Tom's installed and it is very nice. Despite the surging that I am about to describe, I will say I can already feel the difference. Thanks Tom!
Now to the bad. I had this surging before and after installing his tune (just making sure everybody knows: i'm not faulting him in any way, shape, or form). It seems to do it at idle when I first start it up, during constant speeds on the highway, and sometimes intermittently through the RPMs. After it warms up, the surging at idle and at speeds seems to calm down if not completely go away. Sometimes. It kinda feels like a dirty EGR valve. Though, for some reason, I'm thinking I read or heard that SVTs don't have EGRs??? Anybody got any ideas with this one? Vacuum leak? I've only got 41k miles on it.