The injector adjustment is for all injectors. Nistune sucks. The software is too controlling by the author and he's made the whole process of using it more difficult than it needs to be. You can't even use other software with it once you've changed to a nistune board because the nistune software protocal is completely different from the usual software process. If you want to pay for an over priced system that's nothing more than another eprom emulator, then go for it.