l need to know what a bmw itb does? how it works? how much it costs? Anything please!! For a 2000 bmw 328i

ITB stands for individual throttle body, which means for each combustion cylinder have one throttle body. the function is to controls the amount of air flowing into the engine, in response to driver input.

compares to other Universal throttle body which uses one throttle for all cylinders, the engine response and power output for ITB is better and quicker.

Your engine uses the universal type l think.

Hope this answer your question.