Since the light is on, it means the computer has detected a malfunction within the EST system. This could be caused by several things, including:
* Faulty crankshaft position sensor: This sensor tells the computer where the crankshaft is in its rotation, crucial for proper timing.
* Faulty distributor: If your Cavalier has a distributor (some did, some didn't, depending on the engine), problems within it can affect the spark timing.
* Faulty ignition control module (ICM): This module controls the spark to the plugs.
* Worn or damaged ignition components: Wires, coil, etc.
* Low fuel pressure: Though less common, it can indirectly affect the spark timing calculation.
* Problems with the computer itself: Though less likely, the car's computer could have a fault impacting the EST system.
You'll need to get the trouble codes read. This is crucial to pinpoint the exact problem. You have several options:
* Auto parts store: Most auto parts stores (like AutoZone, Advance Auto Parts, etc.) offer free diagnostic code reading services. They can plug a scanner into your car's OBD-II port (usually under the dash) and retrieve the codes.
* Mechanic: A mechanic can diagnose the problem and fix it. This is often the best option, as they have the experience to interpret the codes and know how to troubleshoot.
Do not ignore the light. Driving with the EST system malfunctioning can lead to poor engine performance, reduced fuel economy, and potentially damage to the engine over time. Get it checked out as soon as possible.
