What does code 21: Purge switchover valve-open or shorted mean? It's a 95 e320 btw.

 

Shot in the dark.....
Suggest that the evaporative emmission purge valve which allows the engine to "consume" air that has passed over the activated charcoal in the evap loss container is dead.
This will likely be a black device sited somewhere allong the tube that goes from the charcan to the engine manifold/intake. It will have wires going to it. Remove the valve and see if it changes position powered to unpowered. 12v?
Stuart

 

that's one hell of a shot in the dark. thanks Stuart.