im not sure wether my wiring harness is the na or the t 2 my car is swaped but how can i tell the difference i have a fcd on it with an n333 ecu so i was just wondering because im planning on the rtek ecu upgrade and i dont wanna run into problems

 

The NA and TII harnesses for S4 are the same, save for one wire. So either harness works. As for the FCD, you won't need it after the RTek.

 

so i shouldnt have any problems when getting the rtek 2.1 for the s4 thats good i guess it was the s5 i was reading about them having prolems with a na t2 swap