Buick LaCrosse 2.4 has large idle throttle opening and large air flow.

Does the subject want to ask "the reason why Buick LaCrosse 2.4 has a large idle throttle opening and a large air flow"? Throttle fault, sensor fault.

1. Throttle fault: Throttle is an important part to control air entering the engine. Throttle failure will lead to abnormal airflow, which will lead to unstable engine idle speed or excessive idle speed.

2. Sensor failure: Sensor failure will cause the engine control unit to receive the wrong signal, which will lead to unstable engine idle speed or excessive idle speed.