Ahhhhhhh, that makes senseThe exhaust valve cycles (open-close-open) when turned on. it's checking to make sure the servo motor is working properly but the valve is only really used between 4000 - 7000 rpm roughly...it closes to make the bike pass noise restriction requirements.
Removing the cable by itself shouldn't give you the CEL, its when you disconnect the servo motor wire harness. Your bike doesn't know if the cable is connected or not, it's just testing the motor at start up
As an FYI I tested my bike with the cable disconnected and I can feel the difference at 4000RPM, the bike is smooth in second gear. However with it connected you can feel a push-pull sensation. None of this however corrected the sound I'm hearing (High pitched metal sound - piercing). Oh well. Learned something new either way. Just have to keep listening to music while im riding to hide the noise till the dealer sorts it out.
Thanks again mate, your a legend