* Throttle Position Sensor (TPS): This sensor tells the engine control unit (ECU) the position of the throttle plate. A faulty TPS can send incorrect signals, leading to erratic engine behavior, including jerking and the illumination of both lights. This is a very common cause.
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine. A malfunctioning MAF can cause the engine to receive an incorrect air/fuel mixture, resulting in poor performance, jerking, and the activation of the warning lights.
* Throttle Body: The throttle body itself could be dirty, sticking, or have internal problems. A build-up of carbon can restrict airflow, causing similar symptoms.
* ECU (Engine Control Unit): While less common, a failing ECU could be misinterpreting signals from other sensors, leading to the erratic behavior and illuminated lights. This is a more expensive and difficult-to-diagnose problem.
* Wiring Harness: Damaged or corroded wiring in the throttle control system could interrupt signals, causing erratic engine behavior. This is especially likely in an older vehicle.
* Vacuum Leaks: A leak in the vacuum lines that control the throttle can also lead to inconsistent engine performance and the activation of warning lights.
What to do:
1. Don't drive the car extensively. Continuing to drive with these lights on could cause further damage.
2. Get the codes read: A mechanic can use an OBD-II scanner to read the diagnostic trouble codes (DTCs) stored by the ECU. These codes will pinpoint the likely source of the problem. Many auto parts stores offer free code reading.
3. Address the problem promptly: Ignoring the issue could lead to more serious engine damage. Based on the codes and the mechanic's diagnosis, the necessary repairs can be made.
The jerking sensation points towards a problem with the engine's ability to control its power delivery, making a quick diagnosis and repair crucial. Don't attempt to diagnose or fix it yourself unless you have significant automotive experience; a misdiagnosis could lead to further complications.
