Common Issues:
* Oxygen Sensor (O2 Sensor) Malfunction: This is a very frequent culprit. O2 sensors monitor the exhaust gases and help regulate fuel mixture. A failing sensor can lead to poor fuel economy, rough running, and the check engine light.
* Mass Airflow Sensor (MAF) Problem: The MAF sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can cause inaccurate fuel delivery, leading to performance issues and the check engine light.
* Catalytic Converter Issues: A failing catalytic converter can cause decreased performance, poor fuel economy, and trigger the check engine light. This is often more expensive to repair.
* Spark Plugs/Ignition Coils: Worn or faulty spark plugs or ignition coils can cause misfires, resulting in the check engine light.
* PCV Valve (Positive Crankcase Ventilation): A clogged PCV valve can cause excessive crankcase pressure, potentially damaging the engine and leading to the check engine light.
* Throttle Position Sensor (TPS): This sensor monitors throttle position. A faulty TPS can affect fuel delivery and cause the engine to run poorly.
* Crankshaft Position Sensor (CKP): This sensor tells the engine's computer where the crankshaft is in its rotation. A failing CKP sensor can prevent the engine from starting or running smoothly.
* Low Coolant Level: While not always directly causing the light, low coolant can trigger a sensor related to engine temperature and illuminate the light.
* Gas Cap: A loose or faulty gas cap can allow fuel vapors to escape, triggering the check engine light. This is often a relatively easy fix.
Less Common, but Still Possible:
* Engine Control Module (ECM) Problems: While less frequent, problems with the ECM itself (the car's computer) can cause various issues and illuminate the check engine light. This is usually a more serious and expensive problem.
* Various other sensors: A multitude of other sensors contribute to the engine's function. Failure of any of these (e.g., camshaft position sensor) can trigger the light.
What to Do:
1. Get the Diagnostic Trouble Code (DTC): The most important step is to get the specific trouble code from your car's computer. You can do this with a relatively inexpensive OBD-II code reader from an auto parts store. This code will give you a much more precise indication of the problem.
2. Consult a Repair Manual: Once you have the code, consult a repair manual specific to your 2004 Dodge Stratus to understand the potential causes and repair procedures.
3. Seek Professional Help: If you're not comfortable diagnosing and repairing the issue yourself, take your Stratus to a qualified mechanic. They can use their diagnostic equipment to pinpoint the problem and make the necessary repairs.
Ignoring the check engine light can lead to further damage and potentially more expensive repairs down the road. Addressing the issue promptly is recommended.
