How To Clean Exhaust Temperature Sensor

If you’ve ever owned a car before, the chances are you’ll have come across the exhaust temperature sensor at some point or another. This small device is typically located somewhere within the exhaust system of your car and has a few different responsibilities. There are a number of reasons why your car may fail its MOT test, but one common error is due to the exhaust temperature sensor detecting that the temperature from the exhaust pipe is too low.

When this occurs, it’s clear that something needs to be fixed urgently because there could be several issues with the car that need addressing as soon as possible. Luckily for you, we’ve got everything you need to know about cleaning an exhaust temperature sensor on a car!

What Does the Exhaust Temperature Sensor Do?

The exhaust temperature sensor is a small device that is fitted to the exhaust pipe of your car. Its job is to measure the temperature of the exhaust gases as they leave the engine. This information is then relayed to the car’s onboard computer so that the car’s engine can be properly managed.

The exhaust temperature sensor can provide a number of different readings to the car’s computer, including the temperature of the gas, the rate of change of the gas temperature and the status of the catalyst within the exhaust system. A malfunction of this sensor will often result in an error code being displayed within the car’s computer system. This can sometimes lead to the car’s engine management system being disabled as a safety precaution, which means that the car is unable to drive as usual.

Check an Exhaust Temperature Sensor

Most exhaust temperature sensors are fitted inside the exhaust pipe, so your first job is to get the car onto a ramp or something similar. Now, once you’re in the right position, pop open the engine bay and locate the exhaust pipe. You should be able to see the exhaust temperature sensor that’s fitted to the inside of the pipe. You’ll notice that the exhaust temperature sensor is usually fitted with a small wire that runs all the way back to the car’s engine.

Again, the sensor has a small temperature probe on the end that goes inside the exhaust pipe. When you’ve located the sensor, check the wire and the temperature probe to see if they’re covered in anything unusual, such as oil or dirt. If they are, you’ll need to clean the excess away before you proceed as this will affect the readings from the sensor.

How to Clean an Exhaust Temperature Sensor

In most cases, you’ll be able to clean the exhaust temperature sensor with a little bit of wire wool. This is because most sensors are fitted with a ceramic element inside that’s designed to withstand the high temperatures of the exhaust gases.

However, if you feel that the sensor is particularly dirty, we’d recommend that you fit a new one instead. This is because it’s likely that the dirt and grime could be caked tightly around the ceramic element inside the sensor. This could make it pretty difficult to clean away. Alternatively, you could use a special sensor cleaning spray to get rid of any dirt that is on the outside of the sensor. Bear in mind that you should only clean the outside of the sensor, as you don’t want to mess with the ceramic element itself.

Possible Causes of an Incorrect Reading From the Exhaust Temperature Sensor

There are a number of different things that could affect the readings from the exhaust temperature sensor, including:

A dirty sensor: If the exhaust temperature sensor is dirty, it’s likely that the sensor will be unable to detect the correct temperature of the exhaust gases. This can lead to the car’s engine management system incorrectly adjusting the car’s fuel and ignition settings.

A faulty wiring loom: If there is a break in the wiring loom that runs between the sensor and the engine control unit, it could result in an incorrect reading being sent to the car’s computer system.

A faulty engine control unit: If the engine control unit is faulty, it’s likely that it won’t be able to interpret the readings from the exhaust temperature sensor correctly.


If the exhaust temperature sensor detects that the temperature from the exhaust pipe is too low, it’s clear that something needs to be fixed urgently. We recommend that you check the sensor for any signs of dirt or grime and clean it away with some wire wool.

If the sensor is particularly dirty, we recommend that you fit a new one instead. Keep an eye out for any unusual readings from the sensor and be sure to clean the sensor thoroughly if you spot any signs of grime. If the sensor is faulty or broken, it’s best to replace it with a new one to avoid any further issues.

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