What is the cause of low idle speed?

Low idle speed can be caused by several factors, including a vacuum leak, which allows excess air into the engine, disrupting the air-fuel mixture. Other potential causes include a malfunctioning idle air control valve, dirty or faulty fuel injectors, or issues with the throttle body. Additionally, problems with the ignition system, such as worn spark plugs or faulty ignition coils, can also lead to an unstable or low idle. Regular maintenance and diagnostics can help identify and resolve these issues.