EGR Pressure Feedback Sensor: Important Things to Know
- The EGR sensor, otherwise known as the DPFE (delta pressure feedback of the EGR) sensor, monitors the air that goes back into the air intake from the exhaust. The DPFE sensor can detect pressure changes and will send signals to the EGR system based on the readings.
- If the vehicle’s computer system detects any trouble with the EGR sensor, be it the signal or the circuit, this will prompt the Check Engine Light to come on. A faulty sensor can cause engine performance problems and increased emissions.
- The re-routed gases will eventually cause carbon and other particles to build up, clogging the valve. To remove carbon buildup or any blockage, EGR valve cleaning is recommended.
To generate engine power, air is mixed with fuel and ignited to create energy. This mixture, however, is not completely burnt. The unburnt mixture leaves the exhaust as harmful gases such as nitrogen oxide that pollutes the atmosphere. To reduce harmful car emissions, improve fuel efficiency, and lower cylinder temperatures, some of the exhaust gases are routed back into the engine’s combustion chamber. By reusing exhaust gases, a better portion of the mixture is burned off. This is how the engine gas recirculation (EGR) system works.
On older vehicles, mechanical EGR valves are used, while in modern automobiles, an electronic EGR system is controlled by the vehicle’s computer. The EGR valve, which links the exhaust manifold to the intake manifold, is operated through a vacuum or a built-in step motor. It basically controls the flow of the recirculated exhaust gases according to the engine load. The valve opens to increase flow, and it closes to reduce pressure. It operates based on the signals sent by the EGR pressure feedback sensor.
What does the EGR pressure feedback sensor do?
The EGR sensor, otherwise known as the DPFE (delta pressure feedback of the EGR) sensor, monitors the air that goes back into the air intake from the exhaust. The DPFE sensor can detect pressure changes and sends signals to the EGR system based on these readings. The valve may adjust the flow accordingly by opening or closing. This way, the amount of exhaust that goes into the intake manifold can be controlled.
What does DPF mean?
DPF, which stands for diesel particulate filter, is found in the exhaust system. This traps and stores soot or diesel particulate matter from the exhaust gas of a diesel-powered engine, so this will not be released into the atmosphere. Like the EGR system, the DPF also helps reduce noxious car emissions.
The substances trapped in this filter eventually have to be emptied. This is done by burning off the soot or particles that are deposited in the filter. This will regenerate the DPF and re-start the cycle of collecting noxious particles. A DPF sensor monitors the level of soot expelled by the engine.
This filter may fail due to a clogged EGR valve. Once the EGR is clogged, this increases the amount of soot or particulate that is passed on to the filter. Faulty sensors, among other things, can also cause its breakage or failure due to unregulated back pressure. The DPF may be cleaned from time to time to remove the blockage, although in some cases, it would be best to just replace the clogged filter.
What are the most common EGR pressure feedback sensor symptoms?
If the vehicle’s computer system detects any trouble with the EGR sensor, be it the signal or the circuit, this will prompt the Check Engine Light to come on. This will alert you of any possible problem with the sensor. The problem can be accurately diagnosed through a scanner that will reveal the trouble codes.
Once the sensor fails, the vehicle will suffer from these issues:
Poor engine performance
A faulty EGR sensor cannot accurately detect any change in pressure in the EGR system. This will send a false reading or signal. The EGR system will not perform well or will not operate accurately, and this will affect engine performance. The PCM (power train control module) valve, which regulates the amount of air that is mixed with fuel, will not come up with the right air-fuel ratio, most likely producing a lean mixture as the PCM may detect decreased flow of exhaust air. As a result, the vehicle may suffer from rough idling, engine hesitation, and loss of power. Fuel efficiency will also be compromised.
A bad EGR sensor will keep the EGR system from working properly. The valve may not open or close as needed to control the pressure or flow. The exhaust gases may not be recirculated in the right way, leading to an increase in emissions of harmful gases. Because of this, the vehicle may fail an emissions test.
The EGR system must be checked if you experience any of these symptoms or troubles. This way, you can address the problems early on and prevent further damage.
Can the EGR pressure feedback sensor be cleaned?
The EGR returns a portion of the exhaust gases to the combustion chambers, where it is burned. In effect, this lowers the cylinder temperatures during combustion, which prevents poisonous oxides from forming. The re-routed gases, however, may cause carbon and other particles to build up. This can eventually clog the EGR valve, which may be stuck open or close, along with other passages.
To remove the carbon buildup or any blockage, EGR valve cleaning is recommended. This is best handled by professionals since proper care should be observed to prevent damage to other components. Do-it-yourselfers (DIYers) and weekend mechanics may also perform the EGR valve cleaning using some throttle body cleaner for the valve and rust penetrant for the retaining bolts. The old gasket may also be replaced. In the case of an old or worn-out EGR sensor, the best solution is to replace it rather than try to clean or fix it.
How can you find the right EGR sensor for your vehicle?
To find OE (original equipment)-equivalent replacements, make sure that the EGR sensor that you will get is built to the specific make and model of your vehicle. This will guarantee exact fit and straightforward installation. It also will not hurt to check the product descriptions for the terminals, connections, and other configurations. See if the sensor has been tested for function and quality or if this is covered by a warranty.
How much does it cost to replace a faulty EGR sensor?
A replacement for the EGR pressure feedback sensor may cost less than $20 to over $100. The EGR sensor may be bought as a single unit or as a kit complete with the valve. The price of the EGR also varies depending on the brand or manufacturer and your vehicle’s specifications.
EGR Pressure Feedback Sensor: How to Find the Right One
The exhaust gas recirculation (EGR) valve allows your vehicle to be more efficient in completely burning your fuel by recirculating a small portion of your exhaust gasses back into the engine's combustion chamber. You'll get better mileage and less noxious emissions when you have this device installed on your car or truck. A common problem that occurs in this device is when the EGR pressure feedback sensor starts to fail, causing it to send wrong data to your EGR valve. This will result in rough idling and poor acceleration so you'll need to replace this sensor right away.
Clean it or replace it?
Most of the time, you simply have to clean your EGR valve and the entire system will work like new again. Since the EGR valve reuses exhaust fumes, the valve could collect a buildup of carbon deposits, which could block it and cause idling and acceleration problems. You can easily take out the EGR valve and clean it with some mild solvent. If this doesn't solve the problem, then you'd better have a qualified mechanic take a look at it for you, or you can use a scan tool to narrow down your EGR valve's problem. No amount of cleaning can fix your EGR valve, especially the EGR pressure feedback sensor sensor, so we strongly advise that you replace it ASAP.
How much do I need to spend?
Don't worry, the EGR Pressure Feedback Sensor is a small and inexpensive device that you could easily install yourself. Most sensors would run somewhere between $50 to $100, and you could easily find OEM replacements from trusted retailers online. You don't need to confuse yourself with special features or added benefits from these sensors, they pretty much work the same way. You just need to make sure that you get one that is made specifically for your vehicle's make and model, and you're good to go. We recommend that you check your vehicle's manual for information regarding the EGR pressure feedback sensor, so you could easily make an informed choice when buying a replacement online.
How to Replace Your Car's EGR Pressure Feedback Sensor
The EGR pressure feedback sensor on your vehicle is responsible for monitoring the amount of exhaust gases in your engine system and recirculating these gases back for a more complete burn. The sensor itself looks like a small rectangular box and is commonly found near the side of the intake. The most common problem associated with a faulty EGR sensor would be idling issues, which could result in lower fuel efficiency, so it's best to have it replaced ASAP. Don't bother wasting money by hiring a mechanic since this is a DIY task that you can easily finish in your own garage. All you'll need would be a wrench and a replacement sensor along with a couple minutes of your time.
Difficulty level: Moderate
Things you'll need
- Wrench set
- Compatible EGR pressure feedback sensor
- Car manual
Step 1: We advise you to work in a safe and open area where you'll have enough room to work with. Allow your vehicle's engine to cool down before you start working, since you will be dealing with components that could get very hot and you could burn yourself if you aren't careful.
Step 2: Begin by disconnecting the negative battery cable from your car's battery, so you would avoid accidental electrocutions or short circuiting your sensor.
Step 3: Locate the EGR pressure feedback sensor, which is usually located near the master brake cylinder and the heater hoses on your engine firewall. If you need help locating this particular sensor, then you might want to browse your manual, as it could be located in a different place in your vehicle.
Step 4: Once you've found the EGR sensor, you simply need to loosen the bolts that are securing it in place so you could pull it off from its mount. Disconnect the wires and rubber vacuum hoses that are connected to the sensor and you should be able to pull it out entirely.
Step 5: From here, all you'll need to do is reattach the hoses and wires to your replacement EGR pressure feedback sensor and bolt it back into place.
Step 6: Reattach your negative battery cable to your car's battery and you're done!