Possible causes include:
* Faulty oxygen sensor(s): These sensors monitor the oxygen levels in the exhaust and help the engine computer adjust the air/fuel mixture for optimal combustion and emissions. A malfunctioning sensor is a very common cause of this light.
* Catalytic converter problems: The catalytic converter reduces harmful emissions. If it's damaged or failing, the light will illuminate.
* Mass airflow sensor (MAF) issue: The MAF sensor measures the amount of air entering the engine. A faulty sensor can lead to incorrect air/fuel ratios and trigger the light.
* Evaporative emission system (EVAP) leak: This system prevents fuel vapors from escaping into the atmosphere. A leak in any part of the system (fuel tank, lines, etc.) can activate the light.
* PCV valve problems: The positive crankcase ventilation (PCV) valve helps control crankcase pressure and emissions. A clogged or faulty PCV valve can cause issues.
* Other sensor issues: Numerous other sensors (e.g., temperature sensors, throttle position sensor) can also contribute to emission problems and trigger the light.
* Loose gas cap: Surprisingly, a loose or damaged gas cap can cause a small leak in the EVAP system and trigger the light. Try tightening it first.
You need to get the diagnostic trouble codes (DTCs) read. This can be done in a few ways:
* OBD-II scanner: Auto parts stores often offer free code reading services. This is the easiest and cheapest option.
* Mechanic: A qualified mechanic can diagnose the problem and repair it.
Ignoring the light can lead to further damage and potentially more expensive repairs. It's best to address the issue as soon as possible. The specific code(s) will give a much more precise indication of the problem.
