What is a Oxygen Sensor Test?
The oxygen sensor supplies your vehicle’s computer (ECM) with information that indicates when the air/fuel mixture used in the combustion process is too lean or too rich during normal engine operation. The oxygen sensors are mounted in the exhaust path, either in the engine compartment or near the catalytic converter. Depending on variables such as the year, make, model, and engine type, a vehicle may have anywhere from one to five sensors. An oxygen sensor test is a pinpoint test used to evaluate if an oxygen sensor is faulty.
How does a Oxygen Sensor Test work?
The engine in a car, truck, or SUV uses a mixture of gasoline and oxygen in the combustion process. There is a target ratio for this gasoline/oxygen mixture. If the mixture has too much fuel, it is considered "rich," a condition where unburned fuel is present in the exhaust. Too much oxygen is considered a "lean" mixture that can lead to poor engine performance and damage. The oxygen sensor(s) placed in the exhaust pathway measures the difference between the oxygen present in the exhaust and the oxygen present in the atmosphere. Then, by way of a chemical reaction, the sensor produces voltage that is read by the ECM to determine if the mixture is rich or lean and adjust the fuel mixture to move it toward the target.
What are the symptoms of a bad Oxygen Sensor Test?
The most common symptom of a bad oxygen sensor is a check engine light on the dashboard. Interestingly, a faulty oxygen sensor is one of the most common reasons for a check engine light. Other symptoms of a bad oxygen sensor include poor idle, erratic engine operation with the throttle steady, or a hard start condition.
Can I drive with Oxygen Sensor issues?
A vehicle can be driven for a time with a bad oxygen sensor. It is unlikely that major damage will occur. However, a vehicle with a faulty oxygen sensor is likely to put out excessive pollution and have poor fuel mileage. If an oxygen sensor is suspected of being faulty, limit the duration and distance, and avoid aggressive driving.