* Mass Air Flow (MAF) Sensor: This sensor measures the amount of air entering the engine. A dirty or faulty MAF sensor can throw off the air/fuel mixture, leading to the SES light.
* Oxygen (O2) Sensor: These sensors monitor the exhaust gases to help the engine control the air/fuel mixture. A failing O2 sensor can cause poor fuel economy and trigger the light.
* Crank Position Sensor (CPS): This sensor tells the engine's computer the position of the crankshaft. A faulty CPS can prevent the engine from starting or running smoothly, and definitely sets off the SES light.
* Throttle Position Sensor (TPS): This sensor tells the computer the position of the throttle. A faulty TPS can cause poor drivability and illuminate the SES light.
* Idle Air Control (IAC) Valve: This valve regulates the engine speed at idle. A dirty or malfunctioning IAC valve can lead to rough idling and the SES light.
* Spark Plugs and Wires: Worn-out spark plugs or faulty ignition wires can cause misfires, triggering the SES light.
* Evaporative Emission (EVAP) System: This system prevents fuel vapors from escaping into the atmosphere. A leak in the system can cause the light to come on.
* Catalytic Converter: A failing catalytic converter can cause various issues, including reduced performance and setting the SES light.
* Low Coolant Level: While not always directly causing the SES light, a low coolant level can cause overheating, which can indirectly trigger problems that lead to the light.
* Loose Gas Cap: A loose or damaged gas cap can cause a leak in the EVAP system.
To find the cause:
1. Check the gas cap: Ensure it's tightly secured. Sometimes, a loose gas cap is all it takes.
2. Obtain a diagnostic code: The easiest way to diagnose the issue is to use an OBD-I code reader (specific to older vehicles like your 1994 Cutlass). This will give you a specific code that points to the problem area. Auto parts stores often offer free code reading services.
3. Visual Inspection: Check for obvious issues like loose or damaged wires, vacuum leaks, or anything out of the ordinary under the hood.
Without a diagnostic code, it's largely guesswork. Getting the code read is the most efficient way to troubleshoot the problem. Remember, attempting repairs without knowledge can lead to further damage. It's best to consult a mechanic if you're not comfortable working on your car yourself.
