I have a 94 Z28 A4 and when ever i floor it when it gets to about 5500 rpms it will startin bustin out. It does it if i take off from a dead start or if i floor it when i'm doing like 55mph. Its really annoying because i have to left off and then floor it again b4 it will stop bustin out and thats when my competition when racing will catch me. Please, can anyone help me with this problem??

 

if by busting out you mean missfiring, then its probably the optispark, one sign they are going bad is a miss at high rpm.

 

Im asusming when you say "bustin out" your reffering to missing?. I really dont understand your question to be honest.