That's the problem. The car doesn't have it, the ABS/TCS CU is probably only ABS enabled, and the ECU expects to talk to the ABC/TCS CU about both ABS and TCS. It (the ECU) will probably chuck a spaz. Hence needing to Nistune to sidestep the codes.
Bosch 040, Walbro 255, or anything newer, bigger and better able to take ethanol than those.