EGR valve is located on the drivers side of the middle of the engine (just behind the throttle body). The EGR solenoid is a rectangle box near the rear drivers side above the intake manifold. The ecm controls the vacuum signal to the EGR valve. To test, the engine needs to be at operating temp. While idling, place finger under the EGR vavle and lift the diaphram. Engine should run rough , stumble or die. This lets you know the passages are clear. With engine idling, remove the vacuum line on the EGR valve and install a vacuum pump on the EGR valve and pump, engine should run rough, stumble or die. Connect a vacuum gauge to the vacuum line to the EGR valve and rev engine, and you should see a vacuum signal, if not, remove the cover and filter from the EGR solenoid and place finger over filter port, you should see a vacuum signal.
Regarding Charcoal cannister, just make sure the filter under the cannister is clean. The cannister is a round container located next to the air cleaner box.