* Oxygen Sensor (O2 Sensor): A faulty O2 sensor, especially a slow-responding one, can cause problems with the air/fuel mixture, particularly under acceleration when the engine demands more fuel. This is a very common cause of check engine lights.
* Mass Airflow Sensor (MAF Sensor): This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can lead to an incorrect air/fuel mixture, causing hesitation or poor performance under acceleration, triggering the light.
* Throttle Position Sensor (TPS): This sensor tells the computer the position of the throttle. A malfunctioning TPS can cause erratic fuel delivery and poor acceleration, potentially illuminating the check engine light.
* Ignition System Problems: Worn spark plugs, failing ignition wires, or a weak ignition coil can cause misfires, especially under load (highway acceleration). Misfires are a frequent cause of check engine lights.
* Fuel System Issues: A clogged fuel filter, weak fuel pump, or problems with fuel injectors can restrict fuel delivery, leading to poor acceleration and a check engine light.
* Catalytic Converter: A failing catalytic converter can restrict exhaust flow, particularly under high engine load. This can cause engine performance issues and trigger a check engine light. However, this is usually accompanied by other symptoms like reduced power even at lower speeds.
* Vacuum Leaks: Leaks in the vacuum system can disrupt the proper operation of various engine components, leading to performance issues and potentially triggering the light.
* Engine Coolant Temperature Sensor: While less likely to directly cause poor acceleration, a faulty coolant temperature sensor can provide inaccurate information to the engine computer, leading to incorrect fuel mixture adjustments and triggering a light.
Important Note: A 1993 Escort LX is an older vehicle that may not have a standard OBD-II system. You might need a special OBD-I scanner (or a mechanic with one) to retrieve the diagnostic trouble codes (DTCs) stored in the car's computer. These codes will give a much more precise indication of the problem. Simply guessing based on symptoms is unreliable and could lead to unnecessary repairs.
