What is a throttle body on 2004 envoy?

The throttle body in your 2004 Envoy is a component of the fuel injection system used to control the airflow into the engine. It is essentially a valve mounted between the air intake and the intake manifold. Here's how it works:

1. Airflow Control:

- The throttle body has a valve called the throttle plate, which can be opened or closed to regulate the amount of air flowing into the engine.

2. Throttle Position Sensor (TPS):

- The throttle body contains a throttle position sensor (TPS), which monitors the angle or position of the throttle plate. It converts this position into an electrical signal sent to the Engine Control Unit (ECU).

3. Idle Air Control (IAC) Valve:

- Some throttle bodies also house an Idle Air Control (IAC) valve. The IAC valve controls the air that bypasses the throttle plate to regulate the engine's idle speed. It works in conjunction with the ECU to maintain a proper and steady idle.

4. Electronic Throttle Control (ETC):

- Modern vehicles such as the 2004 Envoy typically use an electronic throttle control (ETC) system rather than a direct mechanical connection between the gas pedal and the throttle body. With ETC, the position of the gas pedal is electronically communicated to the ECU, which controls the throttle accordingly.

By managing the airflow into the engine through the throttle plate, the throttle body plays a crucial role in providing optimal air-fuel mixture for combustion, and controlling engine speed through precise airflow regulation.