Thank you very much for the helpful replies.
I am in the US, and, as Tom mentioned, I don't think I have the O2 sensor.
There is nothing sticking out at or around the O2 sensor location.
(I am assuming the O2 sensor location is same in the Mistral crossover http://www.mgcycle.com/product_info.php?products_id=1687 )
So another question, then, is if I buy a set of exhaust and crossover and install them, will my bike run ok?
Will the performance be really really bad?
Will it hurt the engine if I don't install PCIII right away?
Thank you!