1995 Chevy Astro Charcoal canister for emissions

I just found one of the hoses that have come off the canister and I tried to see where it goes to.

The thechnician at pep boys said that I should be able to find it myself and that since it is off that is the reason my van will run okay and then sometimes the engine light comes on and when I shut off the car and start again, it is off. Sometimes when I come to a red light the oil pressure gauge drops and the van stalls.

I guess I should of asked first could that be the reason why my van is running like that and if not what could it be and can you tell me where to attach the hose back to.