Whooshka
Fairly faST old guy
This is exactly what some "fuel management" devices do. They alter the air temp sensor signal sent to the ECU to make it think it's still cold so it richens the fuel/air mix to make it run less lean. Lean = less fuel = better mileage. Also the more lean you can make it (without detonation) the more power. Also more heat. Old saying... "Lean is Mean".If the sensors were open , or go way out of range, a trouble code would be displayed. Same with the voltage being applied to the sensors. But it's also possible the sensor could shift value and the ECM would have no idea that happened, but then the ECM would think the bike isn't warmed up and that would keep it in "open" loop mode.
Once the plastic is off, it only takes a few minutes to check the sensor resistance, to determine if it's in the ball park or not, and to check the voltage being fed to the sensors.