I just did this swap to my 95 impreza. I had to swap out the wiring b/c i went from OBD2 to OBD1. Just glancing at the 1992 legacy service manual in front of me I can see that the wiring pinouts are different from N/A to turbo. A 93 impreza wont be much different. Unfortunately, it looks to me like you would need to swap the wiring as well.