Question about T-VIS

Hey, I have a 91 MR2 turbo, and was wondering if the ECU has detected knock in the past, would the T-VIS rob the car of some power? If so, how would you know that it's the T-VIS and how would you go about fixing it? Thanks.

Info here:
http://www.jekylhyderacing.com/knock.htm

The knock system does not affect TVIS function, but it does affect TVSV function.

Thanks for the info. One more thing, today I accidentally broke the VTV on the air by-pass valve. I was able to make a temporary fix until I can get a new one. However, I cannot remember how it is supposed to be installed. I was thinking port B(black side), was installed facing the air filter but I'm not sure. Anyone know?