I have a pcV only controls 4 injectors, the secondary injector module is not out yet. At a later time you will be able to control all 8 when they release the secondary unit, but when u purchase the base unit pcv all you can control is 4. I will be the first to say that their adds were misleading at first, and now have been changed. It stated that ignition timing could be changed with the pcv as well..... After I got mine i find out that this can only be changed on Harleys and that I will have to buy an additional timing module when they decide to release it....