What is EGR Sensor?

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The most important component of the car that regulates NOx emissions is the EGR system. An EGR valve, EGR cooler, and EGR sensor make up the ENGR system. The EGR sensor’s primary duties include regulating the pressure of exhaust gases, the flow of exhaust gases through channels, and the pintle position of the EGR valve.

What is EGR Sensor?

The exhaust gas recirculation (EGR) valve pintle’s movement and position are detected by the EGR position sensor. The exhaust gas flow through the EGR passageways is measured by the EGR pressure sensor.

The ECU measures the EGR pressure using the EGR sensors, and then uses this data to modify the pressure. The sensor reports a new pressure measurement for validation if there is a change during the pressure measuring process.

One of the most important parts of the EGR system for automobiles with one is the EGR pressure sensor. One of the key parameters that the EGR system relies on to operate is the signal it produces, therefore any issues with it can have an impact on the system’s overall performance. For this basis, you should have the car checked by a qualified mechanic if you think your EGR sensor may be malfunctioning.

EGR Senor Working 

The EGR pressure sensor monitors the pressure being delivered to the EGR system at the expected speed using the exhaust gas pressure from the EGR system. This enables software developers and makers of engine control systems to better understand how to modify the vehicle’s EGR system to react to changing pressure circumstances.

The EGR pressure sensors detect higher pressure when there is a higher engine speed and load. At lower engine speeds and loads, the pressure sensor does, however, detect reduced exhaust gas pressure.

For the EGR system to function effectively, the ECU uses data from the EGR sensors to boost or reduce the pressure inside the system. The EGR valve is slowly opened and closed throughout this procedure until the control unit is completely happy with the EGR system pressure.

The sensor can assist the engine control unit in determining the issue and preventing further system damage if the EGR system discharges very high or extremely low exhaust gases.

Symptoms of a bad EGR Sensor 

For the car to operate efficiently, the EGR system’s effectiveness is crucial. When the EGR sensor malfunctions, one of the symptoms listed below occurs:

1) Check Engine Light Illumination

One of the initial indications of a faulty or broken EGR sensor is the lighting of the check engine light. This light is a dashboard fixture for your car. The check engine light turns on when any EGR system component malfunctions.

The EGR valve is often where the check engine light would direct you, however, it is conceivable that the light might turn on as a result of a symptom rather than a cause. For instance, even when the issue is caused by a malfunctioning EGR sensor, you can still see a check engine light that signals excessive exhaust chemicals or misfires.

2) Rough Idling 

When the car is started or short halted, rough idling happens (i.e., when the engine is warming up at a low speed). When the EGR is continually opened, exhaust gas enters the intake manifold, causing rough idling.

3) Poor Fuel Economy 

When the valve is left open all the time, poor fuel economy frequently results. This is because the gasoline does not burn at the ideal temperature due to the lower temperature, which lowers the vehicle’s performance.

4) Poor Engine Performance 

A bad EGR pressure sensor’s most prevalent symptom is a decrease in engine performance. The EGR system may break down if the pressure sensor in your car gives the computer any false readings. Engine performance difficulties including rough idle, hesitancy and a loss of overall power and fuel economy can be brought on by a broken EGR system.

5) Higher Emission 

The rate at which exhaust gases are emitted rises when the EGR sensor becomes faulty. The EGR valve might malfunction at times, increasing the emission rate. The temperature drops and the fuel cannot burn all the way through if the valve is left open. As a result, there will be an increase in the flow of unburned hydrocarbon gas leaving the exhaust pipe.

High temperatures in the combustor can produce excessive NOx gas if the valve is always closed.

6) Engine Overheating 

Your car’s engine overheating may be caused by a faulty EGR sensor. Your engine may heat up to dangerous levels if this sensor does not effectively transmit pressure to the EGR valve, which will therefore be unable to stop the emission of nitrogen oxides into the atmosphere.

Additionally, it will leave unburned fuel in your exhaust, which might make your car smell strongly of gasoline and lower the efficiency of your fuel or diesel. When the temperature reaches a certain level, your engine will begin to bang.

There are several causes of engine overheating. In most cases, this occurs when a problem with the cooling system prevents heat from leaving the engine compartment. A leak in the cooling system, a malfunctioning radiator fan, a damaged water pump, or a clogged coolant line might be the cause of the problem.

How to replace EGR Pressure Sensor?

For the EGR system to function effectively, the EGR valve must be properly maintained and replaced.

To replace the valve, according to the instructions below:

  1. Start by removing the sensor’s two rubber or composite rubber cables.
  2. Take off the metal lines from the EGR pipe or exhaust manifold.
  3. Next, remove the sensor’s electronic connector
  4. If the hose has to be changed, do so, then attach a new sensor.
  5. A small number of sensors may be attached with clips or other fasteners. It only takes a few seconds to remove the mounting hardware and swap it out for a new sensor.

Function of EGR

The EGR reduces combustion temperatures and thus lowers the quantity of NOx released by returning a small part of exhaust gas to the engine’s combustion chambers through the intake manifold. The primary element of the EGR technology is the EGR valve, which is typically closed.

EGR Sensor Location

On top of the EGR valve is where you’ll find the EGR position sensor. As the exhaust gas pipe must be linked to both the sensor and the valve, EGR pressure sensors are placed near to the EGR valve.

EGR decreases NOx at lower loads while maintaining performance and emissions. At greater loads, a higher rate of EGR greatly decreases NOx while degrading emissions and performance. Therefore, it may be inferred that larger EGR rates can be used at lower loads.