I was wondering the difficulty to swap to the S5 ecu and harness, and what sort of wiring would I have to do to use the S5 ecu. Would I have to rewire the car, or could I find out what parts of the ecu match the wires to parts of the car? Thanks in advance.

 

did you try to search the FAQ? I remember seeing a write up on this.

 

Well, I know the whole switching the front iron's and stuff like that around...I was just wondering how hard it would be to rewire the ecu primarily