1990 Pontiac Sunbird 2.0L Fuel Injected has EGR Valve, I can suck and blow through the hose connected to it, an I supposed to be able to do this, or not...? It looks old, like it's been on the car forever...
You can do a simple test of the valve - take a clean hose into the input - suck on it and place your tongue against the hose - it should hold vacuum and your tongue for about a minute. If it doesn't, replace the valve. They can also get clogged with deposits that can cause problems. For one that old, you may do well to just replace it.
It recirculates the fumes and the air--but a cracked hose is a nightmare if vacuum leak develops--fix it--just get a new hose and happy motoring
