What to Do About a Bad EGR Valve on a 1998 Honda Civic

So the engine in your 98' Civic has began to run rough and performance has fallen far below an acceptable level. You're likely experiencing a rough idle and a bucking or jumping sensation during acceleration, along with a check engine light. Despite the hatred the average driver has for a check engine light, it is actually a good thing cause it leads us to know that your EGR valve has become faulty. You may have to outright replace your EGR valve, but there is something you can do that can prolong this process and possibly save your self some money in the long run.

What the EGR Valve Does

The EGR valve is used to vent a portion of the exhaust back into combustion chamber for a second burn. This process helps to reduce emissions by cooling the combustion process and burning off excess nitrogen related gases, also known as NOX emissions. Your EGR valve is specifically controlled to open and close at specific times; generally when the combustion chamber reaches 2500 degrees and can produce nitrogen gases. A faulty EGR valve will cause your engine to produce more than its fair share of smog and will cause you to fail an emissions test, if your state subjects you to such testing.

Where it's Located

The EGR valve on your 1.6-liter engine is located between the cylinder head and intake plenum, almost in-line with your fuel rail. It looks like a small black cylinder with an electrical connector on top and bolts directly to the lower intake manifold. On older models your EGR valve would have been controlled by the engines vacuum but you will notice your EGR valve is controlled solely by the ECM, so there are no vacuum lines connected. The EGR valve is serviced and replaced as a unit, but you may be able to clean the EGR valve to save your self some money as opposed to replacing it.

Cleaning

Because your EGR valve inlet tube is connected directly to the exhaust, it is subject to the same carbon and soot build up as the rest of your exhaust components. You can remove the EGR valve from the engine and spray the inlet and outlet ports with brake or carburetor cleaner to help remove the carbon and soot build up. The trick here is to hold the valve upside down and allow the cleaner to penetrate through the build up for a few minutes. Pour the cleaner out of the valve and rinse the valve again with brake cleaner. After this process, the valve should look reasonably clean on the inside. Re-install the valve and clear your trouble codes, you may have just saved yourself from having to purchase a replacement.

Removal and Replacement

First thing you will need is a new EGR valve gasket. Remove the two nuts securing the valve to the engine with a swivel socket, extension and ratchet. Because of the tight confines of this side of the engine you may have to use a short 14 mm wrench to reach the rear most nut. Whether you have opted to clean the EGR valve or just replace it, you need to install a new gasket to the engine. Set the EGR valve onto the mating surface and install the mounting nuts. The mounting nuts should be tightened to 27 foot-pounds with a torque wrench. Always clear your trouble codes before driving the vehicle.