Catalytic Converter Damage and Three-Cylinder Misfire: What's the Cause?
2 Answers
Catalytic converter damage and three-cylinder misfire are caused by ignition coil and cylinder wire faults. Causes of three-cylinder misfire in car engines: Ignition fault: The ignition coil and high-voltage wires need to be checked. Ignition coils cannot be repaired and must be replaced if faulty. Fuel injection fault: This may be caused by wiring issues or poor fuel injection pressure. Human operation errors: Such as carelessness or mistakes during maintenance: faults caused by touching, loose connectors, etc. Wear and aging: Untimely maintenance or the use of inferior, substandard, or non-compliant engine oil. Engine fault: If the engine is faulty, it needs to be replaced promptly.
I've been running an auto repair shop for over a decade and have encountered numerous cases of catalytic converter failure accompanied by three-cylinder misfires. Typically, the root cause lies in the ignition system, such as aging spark plugs or faulty ignition coils in the third cylinder, which can lead to unstable ignition in that cylinder. After an engine misfire, unburned fuel mixes into the exhaust, and the catalytic converter is prone to damage from high-temperature residual oil contamination. Therefore, the damage points are usually the spark plugs, coils, or related wiring. Symptoms include engine shaking, poor acceleration, and in severe cases, the check engine light may come on. I recommend first using an OBD scanner to read the fault codes and confirm the cause of the misfire. When repairing, don't just replace the catalytic converter; inspect and repair the ignition components as well. Regular maintenance, such as replacing spark plugs, can prevent these issues, extend engine life, and save both money and hassle.