The sensors don't know where the fuel is injected.
But there's a reason factories are using port-injection over the basicly simpler TB-injection these days.
Emissions is most likely the reason, which shows proper fuel-control is easier/better achieved when you inject fuel right above the intake valve, instead way up in the intake-track at the intake opening.
Cold intake manifolds can cause vaporized fuel to partly fall out of suspension, meaning not all of the carefully measured injected fuel gets to the cylinders at the moment they are supposed to. Even worse, reformed fuel-droplets can 'puddle' inside the intake and be caught and whipped up in a faster airstream and screw up the mixture for that cylinder firing event.
