Controlling an Electronic Throttle Body using a PID controller

Projects Programming
2 
  Setpoint = map(analogRead(2), 0, 1023, 0, 255);

There is no clue, from reading this, exactly what is controlling the set point. Why not?

map() is a pretty expensive way to divide by 4.

  double gap = abs(Setpoint-Input); //distance away from setpoint
  if(gap<100)
  {  //we're close to setpoint, use conservative tuning parameters
    myPID.SetTunings(consKp, consKi, consKd);
  }
  else
  {
     //we're far from setpoint, use aggressive tuning parameters
     myPID.SetTunings(aggKp, aggKi, aggKd);
  }

You don't diddle with the tuning parameters based on how far off you are. You experiment to find tuning parameters, and use them. Consistently.

  int TPS0 = analogRead(0);
  int TPS1 = analogRead(1);

Again, there is no clue what you are reading from. Why not?

  int TPS =  TPS1 - TPS0;
  TPS = map(TPS, -715, 910, 0, 255);
  Input = TPS;

What purpose is TPS serving? None that I can see.