Q: How to replace the EGR Vacuum Solenoid,EGR Valve and MAP Sensor in Kia Optima?A: The EGR system, used in 2001-2006 four-cylinder models, lessens NOx emissions. Also, to replace the EGR valve, remove the engine cover, disconnect the vacuum hose, remove bolts, and lift the valve. Check for carbon deposits and clean or replace them. For the EGR Vacuum Solenoid, disconnect the wiring and hoses, label, remove bolts, and remove the valve. The MAP sensor is connected to the intake manifold and informs the PCM. Disconnect the wiring/hose connections, remove screws, and lift the sensor. Installation is the reverse of removal.