my check engine light is on
Most of my experience is O2 sensor Go to Auto Zone or any other parts supplier who will allow you to borrow an OBD ( On Board Diagnostic)... plug it into the connector (usually under the dash) and it will tell you what's turning the light on. Most cars computers will set the engine to run rich if the sensor fails If you do it yourself (replace sensor .. your car may have 2 .. one at the exhaust manifold another at the Cat, ... the OBD will tell you which one is bad) Good Luck
Go to a dealer or auto shop and ask them, usually it needs like an oil change or a new starter
Search Ford Crown Victoria Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford Crown Victoria Experts