mikez28_mjf

My car is a 98 Z28 A4. When it was stock back in 99' my best mph was only 100 and I ran high 13s. Now with the mods in my sig, my best mph ever was 103.2. I just always thought my car was on the slow side, but I have been reading that some 98 LS1s have false knock which really hurts performance. I always use 93 gas, sometimes 94.

I don't have access to auto tap to see if this is the problem, but there is a dyno about 25 miles away, if I got it dynoed could tell if I was getting false knock?

If so, what is the fix, replacing the sensors with newer version?

1999_SS_M6

In order to tell if you're getting KR or any kind, false or otherwise, you need a diagnostic scanner. You need to see what the PCM is picking up, and a dyno isn't going to tell you that. Sure, it can show you if you have a flat spot in your HP curve, but that could be from KR, weak valve springs, bad lifters, or any number of things.

Best bet would be to get in touch with a buddy that has a scanner (if you don't have one already, or don't have $300 for your own diag. package, now's a good time to make a friend) and see what's going on in there.