You know, I used to be kinda weary of premixing, but my pump, oil injectors, and lines all failed.
I didn't have the money to buy 4 new injectors and a pump, so because I was planning on an rtek anyway, I just chose to get the block off kit.
Another bonus is that it further helps eliminate clutter and potential vaccum leaks.
If you have an S4, you do NOT need to buy the rtek chip in order to remove the omp system, also, Banzai Racing sells the best "kit" to do this for a reasonable price that includes the plate, bolts, and the pipe plugs n shit to block off your injectors. I got one, love it!
www.banzai-racing.com