EGR system is used to minimize nitrogen oxide emissions due to high temperate combustion and it does this through restricting the exhaust gases that gets into the fuel/air mixture. If EGR is functioning at a high rate, the engine may jerk or stall especially after cold starts or during idling, while if the EGR flow is very low, the result may be high temperatures of combustion and a resultant spark knock or even severe engine damage. Most EGR valve failures are caused by the need of cleaning them to clear carbon,and a problem in the EGR circuit will set off a code. While in carbureted & throttle body injection engine, it is diaphragm type , operational by vacuum but in central multiport & sequential fuel injection engine it remains without vacuum control. EGR valve has to be checked by examining the vacuum hoses for the signs of leakage and it also has to be ensured that the EGR solenoid is operational when certain conditions are met by the engine. During component replacement it is important that the correct EGR valve is purchased, and also correct disconnection and connection of the battery is required in such cases in order to avoid problems with the anti theft systems. The process of installing the valve basically includes the following; first, there is always the destruction of the previous valve that is being used depending on the type of valve that is going to be installed; next, surfaces on which the valve is to be mounted are cleaned; third, all the debris that exist around the place it is to be valued is removed since when the water flows, it is likely to cause clogging. Hoses should also be replaced and in the process the VECI label is used to rout the hoses channel For solenoid and switch replacement, similar measure as those taken during the battery disconnection as well as careful handling apply. Lastly, when removing and installing EGR tube, it important not to carry out the work when the engine is hot so as to avoid being burned; and while re-fixing the tube use penetrating oil since it will ease the fixing process.