[sneakyws6]

Uh All ZX6R from 2001 and on have had cats in the exhaust. It was marketed under the KLEEN system and yes just to burst your bubble the 03/04 had a cat in the exhaust as well.

The flame is nothing mroe than un burnt gas igniting in the exhaust and then flaming out the pipe, wont hurt a thing.

 

[sneakyws6]

Bikes tend to not run lean with aftermarket exhaust but actually rich. I ahve seen it everytime on a dyno. We are not talking about old school carb bikes that ran lean, we are talking about 32bit processor computer controlled fuel injected bikes.

Car even run into the same problems now, they tend to run rich when exhaust changes are made.