1. Oxygen Sensor Issues: The oxygen sensor monitors the amount of oxygen in the exhaust gas. Its readings are used to adjust the air-fuel mixture for efficient combustion and emissions control. A faulty oxygen sensor can throw the air-fuel ratio off and trigger the check engine light.
2. Catalytic Converter Problems: The catalytic converter is responsible for converting harmful pollutants in the exhaust gas into less harmful substances. If the catalytic converter gets clogged or malfunctions, the check engine light may come on.
3. Spark Plug or Ignition Coil Failure: A failing spark plug or a faulty ignition coil can cause engine misfires and rough running. These issues can trigger the check engine light.
4. Evaporative Emission Control System (EVAP) Issues: The EVAP system is responsible for preventing fuel vapors from escaping into the atmosphere. A loose gas cap or a problem with the EVAP system components can cause the check engine light to come on.
5. Emissions Control Issues: If there is a problem with the vehicle's emissions control systems, such as the EGR (Exhaust Gas Recirculation) valve or the PCV (Positive Crankcase Ventilation) valve, the check engine light may come on.
6. Faulty Engine Control Module (ECM): The ECM is the vehicle's onboard computer that controls various engine functions. If the ECM fails or encounters problems, it can trigger the check engine light.
7. Transmission Issues: In some cases, the check engine light may come on due to problems with the transmission, such as low transmission fluid levels or a faulty transmission speed sensor.
When the check engine light turns on, it is essential to have the vehicle diagnosed by a professional as soon as possible. An experienced mechanic can use diagnostic tools to retrieve trouble codes stored in the vehicle's computer, which will help identify the specific source of the problem.
