The EGR or exhaust gas recirculation valve was first used in vehicles in the 1970s. It was one of the first ever known forms of green technological innovations that car manufacturers applied in their vehicles. The fundamental function of an EGR valve is to reduce nitrogen oxide emissions, which is very detrimental to health. When combined with moisture and sunlight, these harmful gases turn into smog.
If you're shopping for a new EGR valve, you need to consider several factors in order to make the right choice. First off, you need to know the major types of EGR valve. Basically, all these valves function the same way, but each type has a unique assembly of parts like the pintle or the opening and the diaphragm.
Types of EGR valve
Single diaphragm EGR valve - This is the oldest type of EGR valve. This type is operated by a vacuum, a diaphragm, and the opening. The vacuum directs the flow of pressure to the diaphragm. At a certain temperature, the diaphragm would prompt the valve to open to let some exhaust gas in to lower the temperature in the combustion engine.
Positive back pressure EGR valve - There is usually a "P" stamped on the part code of the valve of this type. In this valve, the exhaust gases freely flow in the pintle shaft. The pressure of these gases controls the movement of the shaft and allows the air to flow inside the engine.
Negative back pressure EGR valve - This type looks very similar to the positive back pressure type, though you can recognize this by the "N" stamped on it. This type is controlled by two things: engine vacuum, which creates back pressure, and impulses, which regulates gas flow into the engine.
Other factors you should consider
Once you have figured out the right EGR valve type for your ride, you need to check on the quality, brand, and price. Quality and brand go hand in hand since well-known labels are known for their durable products and reliable warranties. As for price, it's best to take a look at what various retailers have to offer and compare rates. Don't forget to check if what you're buying already includes all the essential mounting hardware such as gaskets, bolts, and hose connectors. You'd want a replacement that's easy to install especially if you are planning to do it all on your own.