Instead of resetting the light, you should:
1. Get the Diagnostic Trouble Code (DTC): You need to find out *why* the light is on. You can do this in a few ways:
* OBD-II Scanner: This is the best option. Buy a relatively inexpensive OBD-II scanner from an auto parts store (like AutoZone, Advance Auto Parts, etc.). Plug it into the OBD-II port (usually under the dashboard) and it will read the trouble codes. The scanner will likely give you a description of the code as well.
* Auto Parts Store: Many auto parts stores will read the codes for free. Just take your car in and they'll plug in their scanner.
2. Troubleshoot the Problem: Once you have the code(s), you can research them online (plenty of resources are available) or consult a repair manual for your specific Cavalier model. This will give you an idea of what the problem might be. *Some* simple issues (like a loose gas cap) can be fixed easily.
3. Repair the Problem: Fix whatever the DTC indicates is wrong. This might involve replacing a sensor, fixing a leak, or doing more extensive repairs.
4. Clear the Code (After Repair): *After* you've fixed the problem, you can clear the code. Many OBD-II scanners have a "clear codes" function. Some higher-end scanners even let you monitor live data to see if the problem is truly resolved before clearing the code. Driving the car for a few days after the repair, and seeing if the light returns will indicate if the problem was actually solved.
Warning: Simply disconnecting the battery for a short time might clear the light temporarily, but the underlying problem will still be there and the light will likely return. This is a band-aid solution and not recommended.
In short: Don't reset the check engine light until you've diagnosed and fixed the problem. Ignoring it could lead to significant engine damage and costly repairs down the road.
