English 
e emission control system contains an EGR valve, which stands for exhaust gas recirculation. This feeds exhaust products back into the internal combustion system in order to lower the temperature at which combustion occurs. This increases the overall efficiency of the combustion process and eliminates some of the exhaust from being delivered into the atmosphere as pollution.
What Is the EGR Valve?
The EGR valve is responsible for cooling the exhaust valves. This is an important part of the process of exhaust gas recirculation. It also helps to prevent the exhaust valves from overheating, which can wear them out quickly. Thus, an EGR valve is responsible for maintaining the system at full capacity and increasing the longevity of the internal combustion process.
What Does the EGR Valve Do?
The EGR valve injects the exhaust valves with cooled air to help them to remain stable and to not overheat. The EGR valve is also responsible for regulating some other parts of the EGR process, and oversees the quantity of exhaust products that are funneled back into the internal combustion engine system. This helps to regulate the balance inside of the engine so that the exhaust can function properly and so that the engine doesn't become clogged or damaged.
Cleaning or Replacing the ERG Valve
A regular EGR valve cleaning can help to protect the valve and your internal combustion engine for years to come. It's a good idea to clean an EGR valve about once per year. This helps with engine idling problems. It also can help to avoid stalling in your manual transmission vehicle and to increase the fuel economy. If it's broken, you'll need to make an EGR valve replacement right away so that you can prevent further damage to your vehicle from occurring.
Note the Symptoms of a Damaged EGR Valve
When your EGR valve is damaged, there are several things that will happen to your car. First of all, the engine will make unusual sounds while idling. Second, the engine may be more likely to stall. This is particularly true of manual transmissions, but may happen in automatics as well. Finally, the fuel economy of the car will go down considerably. You'll need the following tools and materials:
Wrenches of different sizes
Socket and ratchet set
Philips screwdriver
New EGR valve, if replacing the old one
Plastic scraper
Scratch awl
EGR Valve Cleaning and Replacement, Step by Step
Locate and disconnect the EGR valve. Open up the hood and look on the side of the engine block for the intake system. This is located in a similar place on most vehicles; if you're having a difficult time finding it, consult the owner's manual for additional guidance. Be sure that the vehicle is cold and hasn't been turned on for several hours when you do this, as the valve can otherwise be quite hot and dangerous to work with. Locate the valve, which typically looks like a small mushroom head or flat obtrusion from the intake system. Disconnect the vacuum hose and the electrical connector by hand, exposing the valve
Remove the connective bolts and lift out the gasket. Use a wrench to remove the two connecting bolts on the sides of the valve, the pipe that connects to the base of the valve. Lift out the entire gasket system by hand, being careful not to break or disturb it
Clean the valve passages. The valve passages often become clogged with carbon deposits. Use the scratch awl to get rid of any of these buildups, being careful not to damage the passages themselves
Clean the base and the bottom of the valve. If the valve has any melted or gasket debris materials on the base of the gasket case, clean these up with a plastic scraper. The scraper is helpful in that it won't cause damage to the system
Replace the valve or reinstall. If you're looking to replace the valve, simply set the new valve into the place of the old one, with a new gasket if necessary. Reverse the steps above to install it. If you're not replacing the valve, simply install the old one back into place
