Hello, so I have a 2007 SS 2wd with k&n cold air kit and I'm thinking about ordering the pcm4less efan kit. Do I need to pay for the tune patch for the efans to work or can I do it myself? Years ago I bought hptuners for my 2000 Trans Am and I know I dont have any credits left. Once I purchase credits will I be able to tune it so the efans work properly? Also which type of efans does everyone recommend?