Here's the proper approach:
1. Get the diagnostic trouble code (DTC): This is the key. The check engine light indicates a fault code stored in the car's computer. You need this code to understand the cause. You have a few options:
* OBD-II Scanner: The most reliable method. Buy a relatively inexpensive OBD-II scanner (available at most auto parts stores). Plug it into the OBD-II port (usually under the dashboard), and it will read the DTC(s).
* Auto Parts Store: Many auto parts stores will read the code for free. Just be aware they may try to sell you parts or services to fix the problem.
* Mechanic: A mechanic will have the tools to read the code and diagnose the issue. This is the most expensive option, but it often provides the most accurate and efficient solution.
2. Identify the problem: Once you have the DTC, look it up online. Many websites (like forums dedicated to Dodge Stratus or general automotive repair sites) offer DTC lookup tables. This will give you a clue as to what's causing the light. Common causes include:
* Loose or damaged gas cap: This is a frequent culprit. Make sure your gas cap is securely tightened.
* Oxygen sensor issues: A faulty oxygen sensor can trigger the light.
* Mass airflow sensor problems: This sensor measures the amount of air entering the engine.
* Other sensor malfunctions: Various other sensors can fail and trigger the light.
* Ignition system problems: Issues with spark plugs, wires, or the ignition coil.
* Exhaust system leaks: Leaks in the exhaust system can cause emissions problems.
3. Fix the problem: Once you know what's wrong, you can either fix it yourself (if you're mechanically inclined) or take it to a mechanic. Replacing a faulty sensor or fixing a minor leak is often straightforward. More complicated repairs should be left to professionals.
4. Clear the code (after fixing the problem): After the repair, use your OBD-II scanner to clear the DTC. The check engine light should then turn off. If it doesn't, there might still be a problem that needs attention.
Warning: Simply disconnecting the battery or using a code clearing tool *without* addressing the underlying problem will only temporarily turn off the light. The problem will persist, and the light will likely return. This is not a solution, only a postponement of a necessary repair.
