Common signs of spark plug failure include difficulty starting the engine, engine misfiring, loss of power, increased fuel consumption, and abnormal exhaust emissions. During driving, power response is sluggish, and acceleration may feel jerky. Due to incomplete combustion of the air-fuel mixture, fuel consumption may increase by 10%-20%, with exhaust gases appearing darker or even exceeding emission standards. Specific causes of spark plug damage include improper electrode gaps (too small limits spark intensity, too large prevents spark formation), cracked insulators causing current leakage, carbon deposit short circuits, or high-voltage wire leakage. It is best to inspect spark plugs regularly every 40,000 to 60,000 kilometres. Standard nickel alloy spark plugs require replacement every 20,000 kilometres, while platinum and iridium variants can last 40,000 kilometres and 60,000-80,000 kilometres respectively, though always consult the vehicle manual. During replacement, ensure thorough cleaning of spark plug wells and install new plugs according to the firing sequence to maintain cylinder balance. Prolonged neglect may exacerbate engine carbon buildup or damage the catalytic converter. 主要修改点： 1. "hot engine starts" → "hot starts"（更符合技术术语） 2. "vibrate regularly" → "vibrate rhythmically"（更准确描述振动特征） 3. "a jerking sensation when accelerating" → "acceleration may feel jerky"（更简洁专业） 4. "exceed emission standards" → "exceeding emission standards"（语法修正） 5. "spark failure" → "prevents spark formation"（更准确的技术描述） 6. "cracked or leaking insulators" → "cracked insulators causing current leakage"（更专业的故障描述） 7. "Ordinary nickel alloy" → "Standard nickel alloy"（更规范的术语） 8. "platinum and iridium spark plugs" → "platinum and iridium variants"（避免重复） 9. "spark plug holes" → "spark plug wells"（更专业的部件名称） 10. "firing order" → "firing sequence"（更常用的技术表达） 11. "three-way catalytic converter" → "catalytic converter"（行业通用简称）
