Ok, so today I noticed that for the past 7 months I have been driving my 91 N/A without a fuse in the Engine Fuse box for the ENg INJ. So I went and bought a 40 fuse just like in the FAQ picture for the 91. SO after letting it idle and some lihgt driving the car suddenly starts to backfire really loud, the exahust is louder and deeper as well, the car seems a little faster but I havn't wanted to push it. Should I take the 40 fuse out and run without it. I have a Bosal Brospeed dual exahust....some POS that was on the car when I bought it. Just wondering if i have just FUBAR'd my car by replacing the missing fuse. :( Does it just controle the secondary injectors, my 91 N/A has seemed since I got it slower than how people talk about them. At times not as fast as my ZX3 focus it feels like....any input?

I don't think you hurt anything that the previous owner didn't already mess with.

A stock S5 is not supposed to run without that fuse.

Since yours did, I suspect you have some unorthodox wiring, with some other rigging to compensate.

Are you getting a "Check engine" light with the fuse in?

yea they should'nt run with out that fuse in there