* Throttle Position Sensor (TPS): This sensor tells the computer the position of the throttle plate. A faulty TPS can cause erratic engine behavior, poor performance, and illuminate both the ETS and Check Engine lights. This is often the first thing to check.
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine. A malfunctioning MAF sensor can lead to incorrect fuel delivery, causing similar symptoms and lighting up both warning lights.
* Throttle Body: The throttle body itself might be dirty, sticking, or have internal problems. Cleaning it is a relatively easy first step, but if the problem persists, it might require replacement.
* PCM (Powertrain Control Module) / ECM (Engine Control Module): While less likely, a problem with the car's computer itself could be the root cause. This is a more serious and expensive repair, usually only considered after other possibilities are ruled out.
* Wiring Harness Issues: Damaged or corroded wiring in the system can cause intermittent or permanent problems, triggering the warning lights.
* Low Voltage: In some rare cases, insufficient battery voltage can confuse the sensors and trigger these warning lights.
What to do:
1. Check the OBD-II codes: Get a diagnostic trouble code (DTC) reader (available at most auto parts stores) to read the codes stored in your car's computer. These codes will provide specific clues about what's wrong.
2. Clean the Throttle Body: This is a relatively easy DIY repair. Disconnect the battery, remove the throttle body, and clean it thoroughly with throttle body cleaner. Make sure to follow the instructions on the cleaner carefully.
3. Inspect the TPS and MAF sensors: Visually inspect these sensors for any obvious damage or debris.
4. Professional Diagnosis: If you're not comfortable tackling these steps yourself, or if the codes point to a more complex problem, take your Cavalier to a qualified mechanic for diagnosis and repair.
Ignoring these lights could lead to further engine damage. Addressing the issue promptly is crucial.
