Q: Mechanic said I need a new throttle body because my car won't go into to drive or reverse

If you car does not go into drive or reverse, your mechanic is most likely talking about replacing the valve body inside the transmission. This is part of the transmission that directs transmission fluid to build hydraulic pressure, which is what causes the transmission to go into and out of gear and shift. There are other components as well that help to contribute to the transmission going in and out of gear and shifting correctly, such as the transmission control solenoid and the control module which controls the majority of the transmission functions.

I would suggest having an expert mechanic, such as one from YourMechanic, come to your location to properly diagnose your transmission and determine if replacing the throttle body is the best course of action.