What a throttle body actually does
A throttle body is a butterfly plate in the intake after the MAF. The pedal, or a motor, sets the angle. Air past that plate is load. It is not the MAF and not a carburetor.
The pedal is not a cable on most of these. Drive-by-wire: your foot is a request. A motor opens a butterfly plate in the throttle body. Cable cars pull the same plate. Either way the part is the plate, sitting in the intake after the MAF, before the manifold.
Air has already been counted. The MAF sat upstream and told the PCM how much mass was moving. Then the plate. More angle, more air into the runners. That air is load. The box meters fuel to match. It is not the MAF. It is not the idle air control by itself — that bypass lived around a closed plate on cable cars. This housing is the door.
Carbon films the bore and the plate sticks. The motor fights it. The scanner throws P0121-class codes and the car limps. Do not call it a carburetor. A carb mixed fuel in that hole. This one only meters air.
