Ford Focus idle up issue when at a stop but accelerates normally while driving on Ford Focus

Some Ford Focus owners report experiencing irregular idle issues, such as a rough idle or near stalling when stopped, despite normal acceleration while driving. These problems may manifest as fluctuating idle speeds that feel like the car is about to stall, especially noticeable when the AC is on. Additionally, some owners have reported a loss of power while accelerating to around 55 mph, accompanied by a stuttering sensation. Sudden idle failures can lead to stalling at stoplights, posing risks like loss of power steering. Even after cleaning the throttle body, some drivers still experience rough idling and increased stalling when braking to a stop. Reports of the car shuddering every few seconds while in neutral have also been noted. To address these concerns, it is advisable for owners to check for dirt in the throttle body, inspect for vacuum leaks, ensure the spark plugs and fuel injectors are functioning properly, and verify the cleanliness of the air intake system. Consulting a mechanic for a thorough diagnostic may also be necessary to identify and resolve the underlying issues.