What are the symptoms of faulty spark plugs?

[LaDante]

Symptoms of faulty spark plugs: 1. Difficulty starting the engine - Excessive carbon deposits or accumulated deposits on the spark plugs can increase the spark plug gap, resulting in insufficient ignition energy and making it difficult to start the car; 2. Reduced power - Thick carbon deposits on the spark plugs reduce the shunt resistance, affecting the spark generation at the electrodes, leading to unstable engine operation and decreased power; 3. Excessive exhaust emissions - Spark plug failures can cause the ignition system to malfunction, resulting in incomplete combustion of the air-fuel mixture and the emission of harmful substances before they are fully burned; 4. Abnormal ignition system - Incomplete combustion of the air-fuel mixture leads to fuel wastage.