There are two different Trans-go kits. The less expensive one (SK2004r)fixes a lot of the common complaints in the day to day operation. 2004r-HD2 is the reprogram kit that really gets things poppin'. A note from me. I found the instructions in the SK kit a little difficult to follow. Who ever writes the copy is very "wordy" and you really need to go through them in order to be clear. (or at least I did)