Is EGR sensor same as o2 sensor?

exhaust gas recirculation sensor easy to change? 2 bolts 2 hoses looks like a flying saucer? Walk me thru it.

The EGR valve does have a gasket that you can get at any parts place. You should put on a new gasket when you remove the EGR valve by disconnecting the vacuum lines and removing the two bolts. Clean out any carbon you find in the two exposed passages in the throttle body and in the valve itself, if you intend to clean it instead of replacing it.