What are the symptoms of a bad oxygen sensor?
3 Answers
The symptoms of a bad oxygen sensor are: 1. Decreased engine power, increased fuel consumption, and unstable idle during operation; 2. Excessive carbon content. The working principle of the oxygen sensor is: using a ceramic sensitive element to measure the oxygen potential in the heating furnace or exhaust pipe, and calculating the corresponding oxygen concentration based on the chemical equilibrium principle, to monitor and control the air-fuel ratio of combustion in the furnace, ensuring product quality and meeting exhaust emission standards. The detection method for the oxygen sensor is: 1. Unplug the oxygen sensor connector; 2. Use a multimeter's resistance setting to measure the resistance value between the sensor's 1 and 2 connectors; 3. A resistance value between 4 and 40 is normal, and if the resistance value is abnormal, the oxygen sensor should be replaced.
I've been driving for decades and seen many cases of bad oxygen sensors with quite obvious symptoms. The check engine light on the dashboard staying illuminated is often the earliest warning. While driving, the engine suddenly becomes unstable, with violent shaking at idle that feels like an earthquake. Fuel consumption inexplicably skyrockets, costing dozens more dollars per month on gas - truly heartbreaking. Acceleration feels weak, sluggish when climbing hills or overtaking, with black smoke from the exhaust and a pungent odor. Over time, it may damage the catalytic converter too, making repairs much more expensive. I've developed the habit of regularly scanning for trouble codes to catch issues early, preventing small problems from becoming big ones - this saves a lot of hassle and money.
My car repair experience tells me that a malfunctioning oxygen sensor can mess up the entire engine. The most common symptoms are the dashboard warning light turning on, unstable engine operation, and fluctuating idle speed. The response is sluggish during acceleration, and the power output is like an elderly person struggling to walk. Emissions worsen, such as emitting black smoke or a stronger odor, indicating incomplete combustion. Fuel consumption spikes, wasting money and harming the environment. Over time, system overheating can also damage surrounding components like the catalytic converter, adding extra repair costs. I recommend performing a simple OBD diagnosis if you notice any abnormalities and fixing the issue early to avoid a chain reaction.
