What causes the 2001 Honda Accord to idle unevenly?

[SanMia]

2001 Honda Accord idling unevenly can be caused by throttle body malfunction and spark plug issues. Here are the specific details: 1. Throttle body malfunction: Blockage in the intake tract can lead to unstable idling, and the presence of carbon deposits or oil in the throttle body is the most common cause of rough idling. Carbon buildup in the throttle body affects its opening degree and air intake volume, causing the engine speed to fluctuate erratically during cold starts, accompanied by strong vibrations. Severe oil or carbon deposits in the throttle body, including dirty intake tracts, can make the car difficult to start in cold weather. Cleaning the throttle body is necessary, and it is considered a routine maintenance item. 2. Spark plug issues: Spark plugs can also accumulate carbon deposits, which can be cleaned to restore their performance. Weak sparks from spark plugs in individual cylinders can affect the car's performance. Faulty spark plugs can cause "misfiring" symptoms, but minor faults in individual spark plugs may result in unstable idling.