Can I Drive With a Bad EGR Valve?

Do you suspect that your vehicle has a bad EGR valve and you are wondering if it’s possible to drive with a bad EGR valve? Are you worried that driving with a bad EGR valve might cause engine damage? I have had this issue and I am going to share my experience with a bad EGR valve. In short, it shouldn’t cause any problems UNLESS it is completely stuck open which is very rare. A stuck open EGR valve can cause stalling at idle, no start, rough idle, popping sound, engine misfire, and check engine light.

Can I drive with a bad EGR valve? Technically, you can drive your vehicle with a bad EGR valve, but your vehicle will run rough, shake at idle, and a check engine light will be illuminated. You might also hear popping sounds while driving down the road. However, driving with a bad EGR valve means that your vehicle is producing a lot of nitrogen oxide which pollutes the environment and you will fail the emissions test.

Can I Drive With a Bad EGR Valve?

Can I Drive With a Bad EGR Valve

If you suspect that your EGR valve is bad, or a mechanic has diagnosed this issue, the question is ”Can I drive with a bad EGR valve?” Technically speaking, you can drive your vehicle with a bad EGR valve without any major limitations. You might experience shaking at idle, rough running, and popping sounds, and that’s about it. In some cases where the EGR valve is stuck completely open (which is super rare), you might not be able to start your vehicle.

The question here is more ”Should you drive your vehicle with a bad EGR valve?” The EGR valve helps reduce the creation of toxic nitrogen oxides that are created in the combustion chamber by up to 70%. Driving with a bad EGR valve will mean that your vehicle will produce a lot of toxic gasses for the environment. Also, you won’t be able to pass the emissions test with a bad EGR valve.

Changing your EGR valve can cost you anywhere from $140 to $599. That’s why it’s best if you first try to clean your EGR valve without removing it before replacing it. You don’t have to be an expert mechanic to clean your EGR valve and it will only cost you around $20. If cleaning the EGR valve does not fix your issue, take your vehicle to the mechanic and have it replaced.

How Many Miles Can You Drive With a Faulty EGR Valve

You can continue to drive your vehicle with a faulty EGR valve for many miles as long as the valve is not stuck completely open. Most of the time, the EGR valve can become clogged and trigger a check engine light but no visible changes are present and the vehicle runs as before.

It is difficult to calculate the exact number of miles you can drive with a faulty EGR valve. This is because the amount of stress and wear your car experiences driving a certain distance will depend on many factors such as type of weather, terrain, and road conditions.

Usually, when the EGR valve starts to fail, a simple cleaning does the job. However, if you continue to drive your vehicle with a faulty EGR valve, you risk damaging the valve and no amount of cleaning will fix it. This is why it is important if you determine that the EGR valve is faulty, go to the mechanic shop and have it looked at.

What Does an EGR Do?

What Does an EGR Do

Exhaust gas recirculation – EGR for short – is an important pollutant reduction method in petrol and diesel engines. When an engine runs, the exhaust gas is taken directly after the cylinders. Then, the EGR valve regulates the subsequent mixing of the exhaust gas with the intake air. This means that less oxygen reaches the cylinder, and less oxygen means a lower combustion temperature.

This way, nitrogen oxide quantities can be reduced by up to 70% as the higher the temperature, the more harmful nitrogen oxides are produced in petrol engines. This can also reduce carbon dioxide emissions and fuel consumption.

The EGR valve is a key component of exhaust gas recirculation. It meters the quantity of exhaust gas that is returned. EGR valves come in various designs and models such as pneumatic, electrical, petrol or diesel applications, or with connections for cooling.

Regulating throttles are used in the intake air system in diesel vehicles. They generate the pressure difference required between the exhaust gas side and intake side to achieve the necessary high exhaust gas recirculation rates.

Air mass sensors are required in diesel engines to regulate exhaust gas recirculation. With their help, the mass of the recirculated exhaust gas is calculated indirectly using the reduction of the intake air.

The EGR coolers have been used since simple exhaust gas recirculation has no longer been sufficient to fulfill emission standards. Just like all components in the EGR system, EGR coolers are exposed to the extreme conditions of the aggressive exhaust gas condensate. They must therefore be manufactured from high-corrosion and temperature-resistant materials.

How Do I Know If My EGR Valve is Working?

To determine whether your EGR valve is working or is bad, you have to perform a series of tests. These tests might require basic mechanic skills. I am going to explain the EGR valve testing process as simply as I can. Please follow all of the steps and at the end, you will know if your EGR valve is working or not.

1. Scan the vehicle with an OBD scanner

The first thing you should do is scan your vehicle with an OBD scanner. If you don’t have an OBD scanner, you can grab one on Attach the OBD scanner to your vehicle’s main computer and look for any error codes. The error code associated with a faulty EGR is P0401.

2. Locate and remove the EGR valve

The EGR valve is usually located on the upper air intake of your engine. Once you locate it, you will need to remove it in order to perform the tests to see if it’s working or not. You don’t have to remove the upper air intake in order to remove the EGR valve.

3. Perform a visual inspection of the EGR valve

The first test that you need to perform is a visual inspection. Once you remove the EGR valve, clean it with a WD40 and wipe it with a clean towel. You must clean the EGR valve so you can perform a visual inspection and check for cracks and damages. If the EGR valve has no cracks and passes the visual inspection, perform the next step.

4. Perform a vacuum test

Grab a hand-operated vacuum pump and attach it to the EGR. If you don’t have a vacuum pump, you can grab one on This test will show if your EGR is able to hold a vacuum. An operating EGR valve has to hold a vacuum without dropping off. If your EGR holds a vacuum for a couple of seconds and then drops off, the EGR is faulty.

5. Check for leaks in the EGR valve

The idea behind this test is to check if the EGR valve is stuck in an open or closed position and if it has any leaks. So, grab any kind of colored liquid. I have tested an EGR valve with ATF fluid before and it works just fine. Pour some colored liquid into the opening and check if the EGR valve is leaking. It should not leak at this point and that means that the EGR valve is closed. Now, attach the hand-operated vacuum pump and attach it to the EGR valve. Once you start pumping, the EGR valve should open and the liquid should come out of the bottom.

6. Reinstall the EGR valve

If your EGR valve has failed one of the tests, you will need to get a new EGR valve. You can grab one on If your EGR valve passed all the tests, you can go ahead and reinstall the old one. Some EGR valves don’t have a gasket and you can add a little bit of silicon rubber around the intake hole and bolt it back on.

Igor Iwanowski

I am a certified Automotive Service Excellence (ASE) mechanic since 2018. I specialize in Brake systems, dashboard warning lights, EGRs, general engine problems, EVAP and Emissions issues.

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