What to Do When a Four-Cylinder Misfires?

[MacLincoln]

For a four-cylinder misfire, it is recommended to inspect the spark plugs, ignition coils, high-voltage wires, fuel injectors, and cylinder pressure of the affected cylinder. The causes of a four-cylinder misfire are as follows: 1. Poor contact or excessive resistance in the ignition coil corresponding to the related cylinder, or a damaged ignition coil. 2. Leakage or open circuit in the cylinder's high-voltage wire, excessively large or small spark plug gaps, or carbon buildup between the electrodes. 3. Airflow. The powertrain control module detects an air flow sensor (MAF) output indicating lower than normal airflow, leading to a lean fuel mixture. 4. Intake system. Air entering the intake system bypasses the air flow sensor, resulting in a lean fuel mixture condition. Check for disconnected or damaged vacuum hoses.