* Temperature-related sensors: Sensors like the coolant temperature sensor (CTS) or the oxygen sensor (O2 sensor) might be failing. These sensors often work better when cold and malfunction as they heat up. A faulty reading could trigger the light.
* Transmission issues: Problems with the transmission fluid temperature, a transmission sensor, or even a slipping transmission could cause the light to illuminate after the transmission warms up.
* Exhaust system leaks: A leak in the exhaust system might not be immediately noticeable when the engine is cold but become apparent as the engine heats up and expands, altering exhaust gas readings.
* EGR valve problems: The Exhaust Gas Recirculation (EGR) valve can stick open or closed, particularly when hot, leading to emissions problems and triggering the light.
* Catalytic converter issues: A failing catalytic converter might only show its symptoms after the engine has been running for a while and reached a certain temperature.
* Ignition system problems: Although less likely to be solely temperature-dependent, a failing ignition component (like a coil or wire) could cause misfires that worsen as the engine heats up.
* Mass Airflow Sensor (MAF) Issues: While not exclusively temperature related, a faulty MAF sensor can lead to inaccurate air-fuel mixture calculations, which may be exacerbated at higher temperatures.
Crucially: The check engine light itself doesn't tell you *what* is wrong. You absolutely need to use an OBD-I (for a 1992 model) scanner to retrieve the diagnostic trouble codes (DTCs). These codes provide clues to the specific problem. Auto parts stores often offer free code reading services. Without the codes, any attempt to diagnose the issue is largely guesswork and potentially expensive.
