Originally Posted by huafist
I can't speak authoritatively on 2G's, but on 1G's, the ECU certainly does matter between manual and auto - first reason that comes to mind are the fuel maps being different.
You are correct, the fuel maps are different because the smaller injectors on the auto. Remember, the major differences in the autos are the smaller inj, different cams (for more low end torque), and smaller turbo. So on a stock 1G DSM, it may make a difference.
However, I put a manual ECU in my car (auto) and it worked fine, no problems, but I do have an AFC which will change the fuel maps.
On a 2G though, I think the inj/cams/turbo are the same between auto/manual, correct? If so, it should not be a problem with putting a auto ecu in a manual 2G.