My check engine light came on after I had the ari filter changed. Shouldn't it reset?

I had the air filter changed on my toyota and the mechanics forgot to reconnect the hose from the filter. After a couple of days the check engine light came on. I reconnected the hose but the light still has not gone off. This happened once before and I took it to the dealer and all they did was reconnect the hose. Is there something else that needs to be done?