What are the Symptoms of bad EGR Sensor? | 2022 Replacement cost of EGR System

The EGR system is the most vital part of the vehicle that controls the emission of NOx. The EGR system consists of an EGR valve, EGR cooler, and EGR sensor. The main function of the EGR sensor is to control the flow of exhaust gases through passages, exhaust gas pressure, and the position of the EGR valve pintle. This article explains the symptoms, causes, and replacement cost of a bad EGR sensor. 

What is EGR Sensor?

The EGR position sensor senses the motion and position of the exhaust gas recirculation (EGR) valve pintle. The EGR pressure sensor measures the flow of exhaust gases through the EGR passages.

EGR Sensor

With the EGR sensors, ECU (engine control unit) monitors the EGR pressure and temperature and uses this information to adjust the pressure. If there is a change during the pressure monitoring process, the sensor reports a new pressure value for validation.

The EGR pressure sensor is one of the most critical components of the EGR system for vehicles that are equipped with them. The signal it provides is one of the main parameters that the EGR system uses to function, and any problems with it can affect the overall functionality of the system.

Therefore, if you suspect that your EGR pressure sensor may be having an issue, have the vehicle inspected by a professional technician.

Working of EGR Senor

The EGR pressure sensor uses exhaust gas pressure from the EGR system to observe the pressure being applied to the EGR system at the desired time. This helps PCM designers and manufacturers understand how to adjust the vehicle’s EGR system to adapt to varying pressure conditions.

EGR Sensor working

In case of higher engine speed and load, the EGR pressure sensors observe higher pressure. However, the pressure sensor observes lower exhaust gas pressure at lower engine speed and load.

The ECU takes information from the EGR sensors to increase or decrease the pressure in the EGR system for the efficient working of the EGR system. This process is done by gradually opening and closing the EGR valve until the control unit is fully satisfied with the EGR system pressure.

If the EGR system discharges very high or very low exhaust gases, the sensor can help the engine control unit identify the problem and prevent the system from damage.

Symptoms of a bad EGR Sensor

The efficient working of the EGR system is very important for the efficient working of the vehicle. As the EGR sensor goes bad, it produces one of the below-given symptoms:

  1. Check engine light
  2. Rough idling
  3. Poor fuel economy
  4. Poor engine performance
  5. Higher emission
  6. Vehicle Overheating

1) Check Engine Light

The check engine light illumination is one of the first symptoms of a bad or damaged EGR sensor. This light is installed on the dashboard of your vehicle. When any component of the EGR system goes bad, the check engine light starts illuminating.

While the check engine light will usually point you straight to the EGR valve, it is possible that it might come on due to a symptom instead of a cause. For instance, you might get a check engine light that indicates excessive exhaust chemicals or misfires, even though the problem stems from a faulty EGR sensor.

2) Rough Idling

Rough idling occurs when the vehicle is started or briefly stopped (i.e., when the engine is warming up at a low speed). This rough idling occurs when the EGR continuously opens, and exhaust gas starts to flow into the intake manifold.

Read More: Symptoms of bad Idle Air Control Valve

3) Poor Fuel Economy

Poor fuel economy usually occurs when the valve is constantly open. This is because the temperature is lower, so fuel does not burn at the optimal temperature, which reduces the vehicle’s performance.

4) Poor Engine Performance

A reduction in engine performance is a most common symptom of a bad EGR pressure sensor. If your vehicle pressure sensor sends any false reading to the computer, it can cause the EGR system to malfunction.

A bad EGR system can lead to engine performance issues such as rough idle, engine hesitation, and a decrease in overall power and fuel efficiency.

5) Higher Emission

As the EGR sensor goes bad, it increases the emission rate of the exhaust gases. Sometimes, the emission rate increases due to improper working of the EGR valve.

If the valve is left open, it reduces the temperature and prevents the complete burning of the fuel. This means that the flow of unburned hydrocarbon gas from the exhaust pipe will increase.

If the valve is always closed, high temperatures in the combustor can create extreme NOx gas.

6) Vehicle Overheating 

A bad EGR sensor can be responsible for your vehicle’s engine overheating. When this sensor does not properly send pressure to the EGR valve, the valve will not be able to prevent the release of nitrogen oxides into the atmosphere, so your engine might increase to dangerous levels of temperature.

It will also leave unburned fuel in your exhaust, and this might cause a strong gasoline smell in your vehicle and reduce the efficiency level of your fuel or diesel. As the temperature gets to a very high point, it will finally lead to your engine knocking.

Read More: Symptoms of a bad EGR Valve

EGR Sensor Location

The EGR valve position sensor is located on the top of the EGR valve. EGR pressure sensors are located close to the EGR valve as the exhaust gas hose must be connected to the sensor as well as the valve.

EGR Sensor Replacement Cost

The replacement cost of an EGR sensor varies according to the area where you live, the vehicle model, and the type of brand. The average replacement cost of the EGR position sensor is from $90 to $150. If you hire labor for this job, the labor cost is $40 to $70, while the new parts price is $50 to $80

How to replace EGR Pressure Sensor?

The proper maintenance and replacement of the EGR valve are very important for the efficient working of the EGR system.

Follow the below-given steps to replace the EGR sensor:

  1. First of all, remove the two rubber or composite rubber hoses from the sensor.
  2. Remove the metal lines from the exhaust manifold or EGR pipe.
  3. Now, disconnect the sensor from the electronic connector
  4. Replace the hose if necessary and install a new sensor.
  5. Few sensors may use clips or fasteners to attach the sensor. This is as simple as removing and replacing the mounting hardware with a new sensor.

FAQ Section

What does an EGR sensor do?

The EGR position sensors detect the movement and position of the exhaust gas recirculation (EGR) valve pintle. The EGR pressure sensors detect exhaust gas flow through the EGR passage.

How long does it take to replace an EGR sensor?

In most models, replacing an exhaust gas recirculation (EGR) valve is not difficult. Using some common tools and a good solvent like carburetor cleaner, you can do it in your garage in about an hour or two, depending on your particular system.

Can I drive with a bad EGR Pressure Sensor?

The efficient working of the EGR sensor is very important for the vehicle and environment. You shouldn’t drive with a bad EGR sensor. 

Whenever the check engine light is on, especially when it is flashing, you should contact a professional to inspect your car. Don’t ignore the illuminating check engine lights, especially if the problem belongs to the EGR system. A faulty EGR system not only causes poor fuel economy and the above-given signs, but it may also make the vehicle unable to start and drive.

What is the function of EGR?

The EGR system works by returning a small portion of exhaust gas to the engine’s combustion chambers through the intake manifold, lowering combustion temperatures and therefore reducing the amount of NOx emitted. The EGR valve is the main component of the EGR system, and it’s normally closed.

Does EGR affect performance?

At lower loads, EGR reduces NOx without deteriorating performance and emissions. At higher loads, an increased rate of EGR reduces NOx to a great extent but deteriorates performance and emissions. Thus, it can be concluded that a higher rate of EGR can be applied at lower loads.

Does removing EGR increase power?

Deleting a vehicle’s exhaust gas recirculation (EGR) system automatically boosts oxygen density in the engine’s air-fuel mixture. This will further result in increased horsepower.

Can you drive without an EGR valve?

Technically you can drive without a working EGR valve. It won’t affect the health of your engine, but it will hurt the environment. The main purpose of your EGR valve is to reduce the number of toxic NOx gases in the environment, so if it isn’t working quite right, more toxic gases will be released into the environment.

What happens when the EGR sensor goes bad?

As the EGR sensors go bad, they generate different issues, such as a reduction in engine performance, increased exhaust gas emission, and reduced fuel economy.

Is it worth doing an EGR delete?

You can improve your fuel efficiency with an EGR delete. That makes the process more efficient while reducing the risk of a diesel particulate filter failure. You may see up to a 20% increase in your fuel economy when using this product option while promoting improved longevity of the engine at the same time.

What are the causes of a bad EGR sensor?

The EGR sensor most commonly goes bad due to a damaged or clogged air filter, damaged oil filter, or intake leaks.

Read More
  1. Symptoms and Causes of bad EGR Cooler
  2. Why your car starts and then die?
  3. Symptoms and causes of bad EGR Valve
  4. Causes of Check Engine Light Flashing

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