"NEED ENGINE SERVICE SOON" lights up on my dashboard of my plymouth '99. what 's wrong? ?

take it to any parts store and have them scan it ,it may just be that it needs reset,they can scan it though and tell you the trouble code for what caused this and they can also erase it,then if it comes back on you know you got a sensor or something going bad on it,good luck.

^ Not always the case in CA they have changed the law and they will no longer check the check engine code. Many of these lights come one with a timer or based on miles.

Consider that if you have a extended warranty you might want to have the service to save your extended warranty. As it could be void if the car hasn't been serviced. Often times if your not worried about that it can be turned off by following a few directions generally found in car forums.

Usually a service engine light or check engine light is emissions related when it illuminates. It could be something simple like a loose gas cap or a bad seal on the gas cap. Find out what the DTC (diagnostic trouble code) is and troubleshoot it from that point.

It could be a thousand different things. Take you car to Auto Zone or Pep Boys. They will read the error with a computer and tell you what the problem is for free.

Go to any repair shop or a competent mechanic,have the car scanned for OBD-II trouble code (s).Ask again with the results,help will be more effective.

may be as simple as you needing to change the oil, but take it to an auto zone or advanced auto parts they will read your code for free and tell you whats wrong.

its made by chrysler