Can You Clean Your Oxygen Sensor? Debunking the Myths

Why Cleaning Your Oxygen Sensor is Ineffective

Over time, oxygen sensors can become contaminated or coated with carbon deposits, leading to poor performance, decreased fuel efficiency, and increased emissions. Many car owners wonder if cleaning an oxygen sensor is a viable solution to restore its functionality. This article explores whether you can clean an oxygen sensor, and if so, is that cleaning effective?

Can you clean an oxygen sensor?

Yes, you can go through the motions of cleaning an oxygen sensor and thinking that you’re actually doing something good for it. You can spray the sensor, soak the sensor, or leave it in place and run the fuel system cleaner through it. But none of those cleaning methods could possibly clean the microscopic pores in the gas-permeable electrodes that make the sensor work. Why? Because the cleaner molecules are larger than the pores in the electrodes. Once the pores get plugged, they stay plugged, no matter how much you soak them. In other words, you can’t clean an oxygen sensor. If the pores are clogged, that’s a sign of an engine problem that must be fixed. If you replace the sensor without fixing the engine problem, you’ll just plug up the replacement oxygen sensor.

The online posts showing you how to clean an oxygen sensor don’t work

First, they show you how to clean the carbon off the protective shield. But the shield is not an operational component. It’s only job is to protect the sensitive ceramic thimble from impact damage. But cleaning it gets you zip as far as increased performance.

The posts also show a spray cleaner cleaning the internal oxygen sensor components. These cleaning methods display a complete lack of understanding of how oxygen sensors and air-fuel ratio sensors work. The liquid cleaner may flush off a surface coating of carbon from the ceramic structure and external platinum electrode, but trust me if the coating is so bad that you think it should be cleaned, the pores in the electrode are already permanently clogged. The only way to restore performance is to fix the underlying cause of the excessive carbon and then replace the oxygen sensor or air-fuel ratio sensor.

Understand how an oxygen sensor is built

Oxygen sensors are constructed with a ceramic cylinder that’s plated on the inside and outside with a porous gas-permeable platinum electrode and protected by an exterior shield with either holes or slots. One electrode is exposed to exhaust gas, while the other is exposed to outside air. The difference in oxygen concentration causes electrons to flow through the ceramic element. The temperature of the ceramic affects its ability to inhibit or conduct the electron flow.

A voltage is produced by the difference in the two amounts. If the amount of oxygen in the exhaust is closer to the amount in the air, the engine is lean and the voltage is low (normally 0.1 to 0.3 volts). If the engine is rich the voltage is high (generally 0.8 to 0.9 volts).

©, 2019 Rick Muscoplat