The exhaust gas recirculation (EGR ) valve recirculates exhaust gases back into the combustion chamber. This helps to reduce the amount of pollution expelled from the vehicle. It is an EPA requirement that all vehicles have an EGR valve. The EGR valve physically moves exhaust gas from the exhaust manifold to the combustion chamber, which means that the valve eventually gets clogged. When this happens, you must remove the EGR valve and either clean or replace it.
Lift the bonnet and prop it open. Make sure the engine is cold. Locate the metal pipe that bolts to the driver's side exhaust manifold. The pipe is approximately 1 inch in diameter and extends up into the engine bay. In some cases, the pipe connects to the passenger's side exhaust manifold. At the base of the pipe, where it connects to the manifold, there's a large nut.
Remove the nut using an adjustable wrench. In some cases, you may need to use liquid rust breaker to loosen the rust between the nut and the manifold.
Follow the 1-inch metal pipe up until you locate the valve to which the pipe connects. This is the easiest way to locate the engine side of the EGR valve, since all vehicles mount the EGR in a slightly different location. This end of the pipe also has a large nut securing it to the EGR valve.
Remove the nut that secures the metal pipe to the engine side of the EGR valve using an adjustable wrench.
Locate the wiring harness that controls the EGR valve. It will be secured to the side or back of the valve, and it will have a plastic locking tab on it. Pull the tab away and release the harness from the EGR valve.
Remove the bolts (usually two) that secure the EGR valve to the engine, using a socket and ratchet. Lift the EGR valve off the engine.