What is the normal range for engine misfire counts?

[LeviLee]

The normal range for engine misfires is monitored by the vehicle's automatic diagnostic system. When excessive misfire counts are detected, the engine malfunction indicator light will illuminate, and corresponding fault codes will be set for diagnosis and repair. Details are as follows: 1. Principle of misfires: During normal gasoline engine operation, fuel and air mix at a specific ratio, are compressed, ignited by spark plugs, and expand to perform work. However, issues in any part of the engine's fuel system, electrical system, or ignition system may cause misfires. 2. Post-misfire measures: Unburned fuel from misfires reacts in the catalytic converter, causing its temperature to rise sharply. If not detected promptly, this can lead to irreversible damage to the converter. Therefore, vehicle diagnostic systems monitor misfires and trigger warning lights with fault codes when counts exceed limits. 3. Note that misfire signals may resemble normal operation: Some modern vehicles, such as those with dual-mass flywheels or hybrid systems, may generate similar signals during normal operation and misfires under certain conditions, making misfire detection challenging with high false-positive rates.