Ford Mustang rough cold start idle issue with persistent misfire after warmup, ongoing troubleshooting required on Ford Mustang

Some Ford Mustang owners report experiencing rough idling during cold starts that continues with a misfire after the engine warms up. These issues may stem from vacuum leaks, which can disrupt engine performance, necessitating a thorough inspection of vacuum lines and connections. Additionally, owners often find that a dirty throttle body or Mass Airflow Sensor (MAF) can contribute to these problems, highlighting the importance of keeping these components clean. Worn-out spark plugs are another common culprit, and their inspection and potential replacement are essential for resolving misfires. Low fuel pressure is also reported as a factor in rough idling, prompting some owners to test fuel pressure to identify any issues. Furthermore, a dirty air filter may lead to misfiring, making it crucial to ensure it is clean and functioning properly. Owners have noted that sensor issues, such as problems with the low side fuel sensor or the Evaporative Emission Control System (EVAP) solenoid, could exacerbate these symptoms. Monitoring dashboard warning lights, like the Check Engine Light (CEL), can provide additional diagnostic information. If these issues persist, consulting a qualified mechanic or Ford dealership is recommended for further diagnosis and repair.