One of the most common reasons for a car to almost stall when idling is a dirty or faulty idle air control (IAC) valve. This valve regulates the amount of air that enters the engine when it is idling. If it is dirty, it can cause the engine to run too lean or too rich, which can lead to stalling.
Symptoms:
* Car idles rough
* Car stalls when coming to a stop
* Idle speed fluctuates
2. Vacuum Leak
Another common cause of stalling is a vacuum leak. A vacuum leak can cause the engine to run lean, which can lead to stalling.
Symptoms:
* Car idles rough
* Car stalls when coming to a stop
* Poor fuel economy
* Hissing or sucking sound under the hood
3. Dirty Throttle Body
A dirty throttle body can also cause a car to stall. When the throttle body is dirty, the engine does not get enough air, which can lead to stalling.
Symptoms:
* Car idles rough
* Car stalls when coming to a stop
* Decreased fuel economy
* Rough acceleration
4. Faulty Oxygen Sensor
A faulty oxygen sensor can cause the engine to run too lean or too rich. This can lead to stalling.
Symptoms:
* Car idles rough
* Car stalls when coming to a stop
* Poor fuel economy
* Check engine light is on
5. Dirty Mass Air Flow (MAF) Sensor
A dirty MAF sensor can cause the engine to run too lean or too rich. This can lead to stalling.
Symptoms:
* Car idles rough
* Car stalls when coming to a stop
* Poor fuel economy
* Check engine light is on
