A misfire occurs when an engine cylinder fails to combust the air-fuel mixture properly. This can manifest as a rough idle, reduced power, poor fuel economy, and increased emissions. A simple analogy is a spark plug failing to ignite the fuel within a cylinder, much like a faulty lighter failing to ignite a gas stove burner. This incomplete combustion can be intermittent or continuous, affecting one or multiple cylinders.
Addressing such engine trouble promptly is vital. Continued operation with compromised combustion can lead to catalytic converter damage, which can be a costly repair. Furthermore, untreated misfires can cause further damage to engine components like pistons and connecting rods. Historically, diagnosing misfires relied on rudimentary methods, but modern onboard diagnostics (OBD) systems now provide specific error codes, making pinpoint diagnosis and repair much more efficient.