I'm converting my I30 to a 5spd and also ordered an EU. I will be making a patch harness, but since my car is originally an AUTO should the ECU pig tail be of a auto too? However, I already have a spare MT ecu that I will be using...

 

If you are using a 5 speed ECU, then you need only carry over the signals necessary for it to function in your patch harness. The "ECM Terminals and Reference Value" section in the EC portion of the FSM will be your friend. Did you buy the Greddy harness yet? If not, I can make you one that's better and costs less than the Greddy main harness. PM me if you are interested.