Ford Mustang idle drops and stalls when shifting from park, possible computer tuning issue on Ford Mustang

Some Ford Mustang owners report experiencing issues with their vehicle's idle dropping and stalling when shifting from park. These problems may manifest as fluctuating RPM and rough shaking while idling at red lights, indicating an idle issue. Additionally, some owners note random stalling when coming to a stop or while revving the engine, which may be linked to the AC being on. To address idle drop concerns, it is recommended to check for vacuum leaks and clean the idle air control (IAC) valve. Some owners find that tuning adjustments, such as altering the idle speed control (ISC) function or consulting a tuner, can help resolve these idle problems. Furthermore, issues with variable cam timing (VCT), particularly when using ethanol, can cause the vehicle to "buck" at idle. It is advisable for owners experiencing these symptoms to inspect the IAC valve, check for vacuum leaks, and seek tuning assistance to mitigate the idle drops and stalling.