The heater is crucial for the sensor to function properly, especially when the engine is cold. A faulty heater circuit can lead to:
* Poor fuel economy: The engine computer relies on accurate oxygen sensor readings for proper fuel mixture. A malfunctioning sensor leads to a richer or leaner mixture, impacting fuel efficiency.
* Rough idling: Similar to the fuel economy issue, inaccurate readings disrupt the combustion process.
* Failed emissions test: The oxygen sensor is a key component for emissions control.
To troubleshoot, you should:
* Check the oxygen sensor wiring and connector: Look for broken wires, corrosion, loose connections, or damaged pins.
* Check the oxygen sensor heater element resistance (if possible): This requires a multimeter and specific resistance values found in your repair manual. This step is more advanced.
* Inspect the oxygen sensor itself: While the code points to the heater circuit, a failing sensor can also cause this code.
* Verify the power and ground circuits: Ensure the appropriate voltage is reaching the sensor's heater circuit.
It's best to consult a repair manual specific to your 1993 Chevy Blazer for detailed diagnostic procedures and wiring diagrams. Simply replacing the sensor without properly diagnosing the problem might not solve the issue if the underlying problem is in the wiring or a related component.
