Subaru Subaru Impreza 2000-2007 Emissions & Sensors Specifications

Emissions sensors for the 2000-2007 Subaru Impreza are specifically designed for this model range and may not be compatible with other Subaru models due to differences in engine configurations and emissions systems. Always verify compatibility using the vehicle's VIN or consult a Subaru dealership for accurate cross-referencing.

Emissions sensors in the 2000-2007 Subaru Impreza require periodic inspection for contamination or damage. Check the sensors during routine service intervals (every 30,000 miles or as specified in the owner's manual). Ensure the wiring and connectors are intact, and clean the sensor tips if necessary. Replace sensors if they fail diagnostic tests or show signs of wear.

To replace an emissions sensor, locate the faulty sensor (typically near the exhaust manifold or catalytic converter). Disconnect the electrical connector, then use an appropriate wrench to remove the sensor. Install the new sensor by threading it in by hand to avoid cross-threading, then tighten to the specified torque. Reconnect the electrical connector and clear any error codes using an OBD-II scanner.

If the check engine light is on, use an OBD-II scanner to retrieve the error code. Common codes for emissions sensors include P0420 (catalytic converter efficiency) or P0135 (oxygen sensor heater circuit). Inspect the sensor for damage, check wiring, and test the sensor's resistance. Replace the sensor if it fails testing or if the issue persists after cleaning and reconnecting.

To optimize emissions sensor performance, ensure the engine is running efficiently by maintaining proper air-fuel ratios and replacing spark plugs and air filters regularly. Use high-quality fuel and avoid short trips that prevent the sensor from reaching optimal operating temperature. Regularly inspect and clean the sensor to prevent contamination from oil or coolant leaks.