This has been asked, I have read about it but would like to make sure.
 

Will an s4 OMP work fine with an s5 FC?

NO.


-Ted

thank you

To build on this; so you might gain a little more knowledge, the S4 is mechanically operated with a shaft from the Throttle Body to the OMP, the S5 is electrically controlled by the ECU.

You are welcome.

And to further complicate things, , , You could, but you would have to use an earlier OMP with the appropriate front cover and a re-chipped S5 ECU (to avoid limp-mode).

Thank you Nismo and I don't think I want to modify this engine just for an OMP, it has 231K miles and is about to die.

What makes you say its about to die? My buddy's has 240k miles on it and still pulls just and strong as mine. If your worried about not getting enough oil injected into your motor just premix.