Yes, because it deletes the catalytic converter. You can run STX with a header and high flow cat, though. 14.10(E) if you want to look it up.
05 ZX4 ST - parts donor. Daily driver until a rock found the oil filter and locked the motor.
08 S Coupe - autocross toy. Less weight and more tire.
06 Ranger - lowered commuter and parts hauler.