A faulty EGR temperature sensor can disrupt system flow. This can lead to combustion problems and metallic rattling noises in the engine compartment.

This noise, also called engine ping, should be attended to immediately because it could cause severe engine damage if ignored. Your mechanic may also use an OBDII scanner to read the trouble codes in your vehicle’s computer.

  • Engine Knocking or Pinging

When your engine is putting out the smooth rumble you’re used to hearing, but instead, it’s emitting a sound more like rattling or hollow knocking, that’s not something you want to ignore. It could mean that there are serious issues under the hood. The knocking sound is caused by the pre-ignition of the fuel and air mixture inside your cylinders and can lead to severe engine damage if you don’t take action.
Engine Knocking or Pinging

  • Overheat engine

A faulty EGR temperature sensor can cause your engine to overheat when it’s under stress. This is because the exhaust gases are unable to escape into the air, so they end up back in the engine and clog the combustion chambers. This will cause the engine or 30 inch wheels to run inefficiently, which in turn will result in poor performance and high emissions.

  • Serious damage to your engine

A failed EGR sensor is a common problem that can cause serious damage to your engine if not addressed quickly. If you’re experiencing any of the symptoms above, it is likely time to replace your EGR sensor. You can use your repair manual to find out how to do this yourself, or you can go to a professional auto shop that uses manufacturer-approved techniques and genuine Subaru parts.

  • Check Engine Light

One of the most obvious signs that your EGR temperature sensor has gone bad is when you see the Check Engine Light turn on. The car’s computer reads all of the sensors, and when it detects a problem that could increase emissions, it activates the warning light on the dash. It also stores an electronic code that indicates which sensor is responsible.

Check Engine Light

  • The air-to-fuel ratio is off.

A malfunctioning EGR temperature sensor can cause the air-to-fuel ratio to be off, which reduces your engine performance and fuel efficiency. It can also affect your vehicle’s ability to reach higher speeds when you step on the gas pedal. If the problem isn’t fixed, you may experience engine damage over time.

  • NOx

When your vehicle’s EGR system is working properly, it helps to decrease combustion temperatures and regulate oxides of nitrogen (NOx) production. When the EGR sensor fails, it can lead to a significant increase in NOx emissions. 

In addition to an elevated NOx level, you might notice that your fuel economy has decreased. This is because your engine needs the right amount of air and fuel to burn correctly. 

  • The correct combination of air and fuel

You might also find that your vehicle has trouble starting if the EGR sensor isn’t working properly. Your car requires the correct combination of air and fuel to start. So, the failure of this component can lead to your vehicle having a difficult time turning over.

  • Enhanced fuel emissions

The EGR temperature sensor works hand-in-hand with the exhaust gas recirculation valve solenoid to control the flow of your car’s exhaust gases into the intake manifold. When this system is working properly, it helps lower your car’s harmful emissions and improve engine performance and fuel efficiency. When this sensor begins to fail, however, it can cause several issues. You can contact XM Car Wheels if you want to know more about the failing EGR temperature sensor. 

Enhanced fuel emissions

  • The decline in your fuel economy

Another symptom you might notice is a decline in your fuel economy. Since a properly functioning EGR temperature sensor is necessary to ensure that the air/fuel ratio in your car’s engine is optimal, this part must be working properly. When it isn’t, your engine will burn more fuel than it should, and it will decrease your gas mileage as a result.

  • Failed Emissions Test

The emissions system in your car works to take burnt fuel and other harmful gasses, transform them into water and carbon dioxide, and then pump them out of the exhaust pipe. A failing EGR sensor or a bad oxygen sensor can throw off the entire system, which could result in failed emissions tests.

  • Failing mass airflow sensor

A failing mass airflow sensor is another common reason why you might fail an emissions test. This sensor measures the amount of air that is entering your combustion chamber and then regulates the fuel mixture based on this information. If it begins to fail, your air/fuel mixture will be too rich, which leads to unburned fuel escaping into the exhaust.


In some cases, you may be able to fix a bad EGR temperature sensor by cleaning it. Over time, carbon can build up on this part, and it can cause it to send inaccurate data to the engine computer, which can then lead to overheating and other issues. This is a simple step that can help you avoid costly repair bills in the future.


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Q1) Can a malfunctioning EGR temperature sensor cause engine overheating?

No, a malfunctioning EGR temperature sensor typically does not cause engine overheating. The EGR temperature sensor is primarily responsible for monitoring the temperature of the exhaust gases entering the EGR system. Its failure may lead to performance issues or increased emissions, but it is not directly linked to engine overheating. However, it is essential to address any engine overheating problems promptly, as they can stem from other issues that require attention.

Q2) How can I diagnose a malfunctioning EGR temperature sensor?

Diagnosing a malfunctioning EGR temperature sensor usually involves the following steps:

Scan for trouble codes: Use an OBD-II scanner to retrieve any diagnostic trouble codes (DTCs) stored in the vehicle’s ECU. Specific codes related to the EGR system or temperature sensor can provide initial indications of a problem.

Visual inspection: Inspect the sensor and its wiring harness for any visible damage, loose connections, or signs of corrosion. Faulty wiring or physical damage could be the cause of the sensor malfunction.

Test the sensor: With the engine off, use a multimeter to measure the resistance of the EGR temperature sensor. Compare the readings to the manufacturer’s specifications. If the readings are outside the recommended range, it indicates a faulty sensor.

Consult professional help: If you’re unsure or lack the necessary tools and expertise, it is advisable to consult a qualified mechanic or technician who can perform a comprehensive diagnosis using advanced diagnostic equipment.

Q3) Can I drive with a malfunctioning EGR temperature sensor?

 It is not recommended to drive with a malfunctioning EGR temperature sensor for an extended period. While the vehicle may still be drivable, a faulty sensor can lead to reduced engine performance, increased emissions, and potential long-term damage to the EGR system. Additionally, depending on your location, a malfunctioning EGR system may cause your vehicle to fail emissions tests or violate local regulations. It’s best to address the issue promptly and have the sensor replaced or repaired by a professional.

Q4) Can I replace the EGR temperature sensor myself?

Replacing the EGR temperature sensor can vary in difficulty depending on the vehicle’s make and model. In some cases, it may be accessible and relatively easy to replace with basic tools. However, in other instances, it may require specialized knowledge and tools due to the sensor’s location and surrounding components. It is recommended to consult the vehicle’s service manual or seek professional assistance to ensure proper installation and prevent any potential damage to the EGR system or other components.