How do I know if its working? what does this do exactly? Is it possible to make the sixth injector turn on when this is on for super warp speedz?

I have the 1984 "K-lambda" CIS, if I hit the switch @ idle, I'll hear the idle speed change (the mixture is getting richer).
@ full throttle, my FI is operating in purely "mechanical" mode, in other words, the position of the air sensor plate soley dictates fuel flow to the injectors.
I have an air/fuel meter hooked up to my OXS, @ full throttle it reads between 13:1 - 12.5:1....