These DTCs will point towards the specific problem. Possible causes are numerous and could include:
* Failing sensor: Oxygen sensor, mass airflow sensor (MAF), crankshaft position sensor, temperature sensor, etc., are common culprits. These sensors are vital for proper engine operation and a faulty one can cause a range of issues.
* Emission system problems: Issues with the catalytic converter, exhaust gas recirculation (EGR) system, or evaporative emission (EVAP) system can trigger the light.
* Ignition system issues: Problems with the ignition coil, distributor cap, rotor, or spark plugs/wires can lead to misfires and illuminate the check engine light.
* Fuel system problems: Issues with the fuel injectors, fuel pump, or fuel pressure regulator can also be the cause.
* Other electrical problems: A variety of other electrical components could be malfunctioning and triggering the light.
What you should NOT do:
* Ignore it: Continuing to drive with a malfunctioning engine can lead to further damage and potentially costly repairs.
* Try to guess the problem: Without a proper diagnostic scan, any attempt at fixing the issue is likely to be a waste of time and money.
What you SHOULD do:
* Get it scanned: Find a mechanic with an OBD-I scan tool capable of reading codes from your 1991 LeSabre. This is the crucial first step to identifying the problem. Auto parts stores sometimes offer free code reading services.
* Research the code(s): Once you have the code(s), research their meaning online (be sure to specify that it's for a 1991 LeSabre and OBD-I).
* Have a qualified mechanic diagnose and repair the issue: Based on the scan results, a mechanic can accurately diagnose and repair the problem.
In short, the check engine light is a warning sign, and ignoring it can lead to significant problems and expense. Get it diagnosed properly to avoid further complications.
