The problem could be anything from something minor and easily fixable (like a loose gas cap) to something major and expensive (like a failing catalytic converter or engine sensor).
To find out the specific issue, you need to:
* Get the diagnostic trouble codes (DTCs) read: A mechanic can do this with an OBD-II scanner. Auto parts stores often offer free code reading services. The codes will give you a much more specific idea of what's wrong.
* Consider the symptoms: Are there other issues happening? Poor performance, rough idling, strange noises, reduced fuel economy? These symptoms can help narrow down the possibilities.
Without knowing the specific trouble codes, it's impossible to say what's wrong with the engine. Ignoring the check engine light could lead to further damage and more expensive repairs down the line.
