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Estimates last updated October 16, 2025

2021 Mazda CX-9 EGR Valve Replacement Cost

The average cost for a 2021 Mazda CX-9 EGR Valve Replacement is between $586 and $666.

Labor costs are estimated between $171 and $251 while parts are typically priced around $415.
This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.

For a more accurate estimate based on your location, use our Fair Price Estimator below.

EGR Valve Replacement

What is an EGR valve?

The exhaust gas recirculation (EGR) valve recirculates a portion of the exhaust gas back into the combustion chamber in order to lower the combustion temperature, which helps your vehicle produce fewer oxides of nitrogen, a major pollutant.

How does the EGR valve work?

The exhaust gas recirculation (EGR) valve is computer controlled and/or electrically or vacuum operated. The valve is commanded open at the appropriate time to also the proper amount of exhaust gas to enter the combustion chamber. This exhaust gas lowers the combustion temperature, reducing the amount of oxides of nitrogen (NOx) created during the combustion process.

What are the symptoms related to a bad EGR valve?

In many cases you would be able drive the vehicle with a failed Exhaust gas recirculation (EGR) valve. However, in some cases the engine may run so poorly you cannot drive the vehicle. A non functioning EGR Valve can result in a pinging or rattling noise from engine when it is under load (when accelerating). More symptoms of a bad EGR valve

Can I drive with a bad EGR valve?

In many cases you would be able drive the vehicle with a failed Exhaust gas recirculation (EGR) valve. However, sometimes the engine may run so poorly you cannot drive the vehicle. If you are hearing a ping or rattling type noise from the engine you should not drive the vehicle.

How often do EGR valves need to be replaced?

Exhaust gas recirculation (EGR) valve replacement is one ot the less common repairs you should expect. Vehicles that are only driven around town on short trips may be more prone to Exhaust gas recirculation (EGR) valve problems as this kind of driving can allow the buildup of carbon deposits in and around the EGR valve. These carbon deposits can restrict the flow of exhaust gases and/or cause the valve to stick open.

Mazda EGR Valve Replacement Cost Estimates

The average cost for a EGR Valve Replacement is between $586 and $666 but can vary from car to car.

Mazda CX-9 EGR Valve Replacement Cost by Year

The average cost for a Mazda CX-9 EGR Valve Replacement is between $586 and $666 but can vary from car to car.

EGR Valve Replacement

Jump to:Commonly associated repairs Related OBD codes Cost estimates by vehicle Cost estimates by year

What is an EGR valve?

How does the EGR valve work?

What are the symptoms related to a bad EGR valve?

Can I drive with a bad EGR valve?

How often do EGR valves need to be replaced?

How are EGR valve issues diagnosed?

An illuminated check engine light could lead to a fault code indicating a problem with the Exhaust gas recirculation (EGR) valve. In this case, the manufacturer suggested diagnostic procedures should be followed to isolate the cause. Removal of the valve may be required for a visual and functional inspections.

How is a EGR valve replaced?

Once the valve is located and made accessible (on some models this can be very easy and on others it can be quite a challenge), relacement commonly involves unbolting the old valve and installing the new one. Rust can develop on the mounting nuts/bolts so penetrating oil should be used prior to attempting removal. Care should be taken around hot exhaust components. While the valve is off, it is a good time to check the be sure the EGR passages are clear.

RepairPal Recommendations for EGR valve issues

Always take care when working around hot exhaust system components and use penetrating oil before removing rusty nuts/bolts. EGR passages should be inspected while the valve is of to be sure they are clear of carbon buildup. When replacing the EGR valve, Vacuum hoses and or electrical connectors attached to it should be inspected and repaired or replaced as necessary.

What to look out for when dealing with EGR valve issues

Care should be taken when working around hot exhaust system components. EGR passages should be checked for carbon deposits whenever possible and cleaned as necessary during valve replacement. Rust can develop on mounting nuts/bolts, penetrating should be used prior to removal.

Can I replace the EGR valve myself?

The location of the EGR valve will most likely to determine if the is a DIY project or not. In some cases removal of additional components will be necessary to gain access to the valve, for testing as well as replacement. You will need to determine if you are up to the task or not. Certain models may also require special tools to remove nuts/bolts securing the valve.