OK,
I have a complete s4 motor, tranny, ecu, and pass side harness. And I have a s5 na with no motor, tranny, ecu, or pass. harness.
So would the driver side harness in the s5 car fit to the s4 ecu? And if so would anything under the motor need to be swapped as far as wiring?


The s5 was gonna get a TII conversion but due to gas prices and lack of funds nee to get the s4 stuff to work.
Worst case I will get a full s5 intake setup, ecu, and harness and use the s4 block.

 

No. Plugs are different from what I understand. You've gotta keep the wiring in the same series (S4-S5). That's what I found when I SEARCHED! Chad! Hehe. My **** runs good!

 

that is what I don't understand? What is the difference in the s4/s5 under the dash? Meaning why would'nt the s5 dash harness plug into the s4 ecu?
All of this is NA.

I would love to put the s4 motor, s4 engine harness, and s4 na ecu into my s5 GTUs since I have all of that stuff and no extra s5 motor.