I just logged my RA for the first time in 3rd gear. I had it in Sport mode/Manual and applied Wide Open Throttle the entire time. Why does my TPS(throttle positioning sensor) say 96.xx% instead of 100%?

Also, without having a wideband (yet) would it be safe to give this information to a professional E-Tuner to adjust for that single knock count of 3 on row #28?